Unityで作成したFirebase接続アプリをandroid向けにビルドするとエラーが発生する

【質問内容】
UnityからFirebaseへの接続を実施しようとしています。
Unity上で動作させる分には、問題なくFirebaseへ接続できるのですが、
androidでビルドしようとすると、以下のような【エラー内容】が発生して、ビルドに失敗してしまいます。

「Assets\Plugins\Android」配下の以下ファイル内において、
com.android.support.support-core-utils-26.1.0.aar
android.arch.lifecycle.runtime-1.0.0.aar
com.android.support.support-compat-26.1.0.aar
com.android.support.support-core-ui-26.1.0.aar
com.android.support.support-fragment-26.1.0.aar
com.android.support.support-media-compat-26.1.0.aar
com.android.support.support-v4-26.1.0.aar
com.google.android.gms.play-services-ads-identifier-16.0.0.aar
com.google.android.gms.play-services-base-16.0.1.aar
com.google.android.gms.play-services-basement-16.1.0.aar
com.google.android.gms.play-services-flags-16.0.1.aar
com.google.android.gms.play-services-measurement-api-16.0.4.aar
com.google.android.gms.play-services-measurement-base-16.0.5.aar
com.google.android.gms.play-services-stats-16.0.1.aar
com.google.android.gms.play-services-tasks-16.0.1.aar
com.google.firebase.firebase-analytics-16.0.6.aar
com.google.firebase.firebase-analytics-impl-16.2.4.aar
com.google.firebase.firebase-app-unity-5.4.4.aar
com.google.firebase.firebase-auth-16.1.0.aar
com.google.firebase.firebase-auth-interop-16.0.1.aar
com.google.firebase.firebase-auth-unity-5.4.4.aar
com.google.firebase.firebase-common-16.0.4.aar
com.google.firebase.firebase-core-16.0.6.aar
com.google.firebase.firebase-database-16.0.5.aar
com.google.firebase.firebase-database-collection-16.0.1.aar
com.google.firebase.firebase-database-unity-5.4.4.aar
com.google.firebase.firebase-iid-17.0.3.aar
com.google.firebase.firebase-iid-interop-16.0.1.aar
com.google.firebase.firebase-measurement-connector-17.0.1.aar
com.google.firebase.firebase-measurement-connector-impl-17.0.4.aar
com.google.firebase.firebase-storage-16.0.5.aar
com.google.firebase.firebase-storage-unity-5.4.4.aar
mainTemplate.gradle.meta
android.arch.core.common-1.0.0.jar
android.arch.lifecycle.common-1.0.0.jar
com.android.support.support-annotations-26.1.0.jar

「com.android.support.support～」と、
「com.google.firebase.firebase～」とが競合しているため、
ビルドに失敗していることまでは分かったのですが、
これをどのようにすればビルドエラーを回避すれば良いのかが分かりません。

同じフォルダに「mainTemplate.gradle.meta」ファイルを配置して、
それを修正すれば、gradleのデフォルトの設定を変更できると思うのですが、
具体的に、どのようにすれば良いのでしょうか。

また、gradleの設定変更等ではなく、このエラーを回避する方法があればご教示お願いします。

【環境】
Unity：2018.3.0f2

【設定】
Scripting Runtime Version：.NET 4.x Equivalent
Api Commpatibility Level：.NET Standard 2.0
Build System：Gradle

【エラー内容】
CommandInvokationFailure: Gradle build failed.
D:\unity\Unity2018_3_0f2\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\OpenJDK\Windows\bin\java.exe -classpath "D:\unity\Unity2018_3_0f2\Editor\Data\PlaybackEngines\AndroidPlayer\Tools\gradle\lib\gradle-launcher-4.6.jar" org.gradle.launcher.GradleMain "-Dorg.gradle.jvmargs=-Xmx4096m" "assembleRelease"

stderr[
D8: Program type already present: android.support.annotation.AnyRes

FAILURE: Build failed with an exception.

What went wrong:

Execution failed for task ':transformDexArchiveWithExternalLibsDexMergerForRelease'.

com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives:

※長いので省略
Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.
Program type already present: android.support.annotation.AnyRes

Try:

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

Get more help at https://help.gradle.org

BUILD FAILED in 18s
]
stdout[
WARNING: Configuration 'compile' is obsolete and has been replaced with 'implementation' and 'api'.
It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html
:checkReleaseClasspath
Download https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-common/16.0.3/firebase-common-16.0.3.pom
Download https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-analytics-impl/maven-metadata.xml
Download https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-analytics/maven-metadata.xml
Download https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-measurement-connector/17.0.1/firebase-measurement-connector-17.0.1.pom
Download https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-iid/17.0.4/firebase-iid-17.0.4.pom
Download https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-iid-interop/16.0.1/firebase-iid-interop-16.0.1.pom
Download https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-common/16.0.3/firebase-common-16.0.3.aar
Download https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-iid/17.0.4/firebase-iid-17.0.4.aar
:preBuild UP-TO-DATE
:Firebase:preBuild UP-TO-DATE
:Firebase:preReleaseBuild UP-TO-DATE
:Firebase:checkReleaseManifest
:Firebase:processReleaseManifest
:preReleaseBuild
:Firebase:compileReleaseAidl NO-SOURCE
:compileReleaseAidl NO-SOURCE
:Firebase:packageReleaseRenderscript NO-SOURCE
:compileReleaseRenderscript UP-TO-DATE
:checkReleaseManifest UP-TO-DATE
:generateReleaseBuildConfig UP-TO-DATE
:prepareLintJar UP-TO-DATE
:mainApkListPersistenceRelease UP-TO-DATE
:generateReleaseResValues UP-TO-DATE
:generateReleaseResources UP-TO-DATE
:Firebase:compileReleaseRenderscript
:Firebase:generateReleaseResValues
:Firebase:generateReleaseResources
:Firebase:packageReleaseResources
:mergeReleaseResources UP-TO-DATE
:createReleaseCompatibleScreenManifests UP-TO-DATE
:processReleaseManifest
D:\FireFoxDL\inhousecoin2_0201B\inhousecoin2\Temp\gradleOut\src\main\AndroidManifest.xml:24:9-31:50 Warning:
activity#com.google.firebase.auth.internal.FederatedSignInActivity@android:launchMode was tagged at AndroidManifest.xml:24 to replace other declarations but no other declaration present
:splitsDiscoveryTaskRelease UP-TO-DATE
:Firebase:generateReleaseRFile
:processReleaseResources
:generateReleaseSources
:Firebase:generateReleaseBuildConfig
:Firebase:prepareLintJar UP-TO-DATE
:Firebase:generateReleaseSources
:Firebase:javaPreCompileRelease
:Firebase:compileReleaseJavaWithJavac
:Firebase:processReleaseJavaRes NO-SOURCE
:Firebase:transformClassesAndResourcesWithPrepareIntermediateJarsForRelease
:javaPreCompileRelease
:compileReleaseJavaWithJavac
:compileReleaseNdk NO-SOURCE
:compileReleaseSources
:lintVitalRelease
:mergeReleaseShaders UP-TO-DATE
:compileReleaseShaders UP-TO-DATE
:generateReleaseAssets UP-TO-D<message truncated>