Android studio の refactoring preview の方法

前提・実現したいこと

Android StudioにてFlutterアプリを作成中、エラーが起きたので、その対処として"Android X migration"をするように書いてあったのですが、Refactoring Previewが見つかりません。

発生している問題・エラーメッセージ

Dart
1D8: Program type already present: io.flutter.BuildConfig
2com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: 
3Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.
4Program type already present: io.flutter.BuildConfig
5	at com.android.builder.dexing.D8DexArchiveMerger.getExceptionToRethrow(D8DexArchiveMerger.java:131)
6	at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:118)
7	at com.android.build.gradle.internal.transforms.DexMergerTransformCallable.call(DexMergerTransformCallable.java:102)
8	at com.android.build.gradle.internal.tasks.DexMergingTaskRunnable.run(DexMergingTask.kt:444)
9	at com.android.build.gradle.internal.tasks.Workers$ActionFacade.run(Workers.kt:335)
10	at org.gradle.workers.internal.AdapterWorkAction.execute(AdapterWorkAction.java:50)
11	at org.gradle.workers.internal.DefaultWorkerServer.execute(DefaultWorkerServer.java:47)
12	at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1$1.create(NoIsolationWorkerFactory.java:65)
13	at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1$1.create(NoIsolationWorkerFactory.java:61)
14	at org.gradle.internal.classloader.ClassLoaderUtils.executeInClassloader(ClassLoaderUtils.java:98)
15	at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1.execute(NoIsolationWorkerFactory.java:61)
16	at org.gradle.workers.internal.AbstractWorker$1.call(AbstractWorker.java:44)
17	at org.gradle.workers.internal.AbstractWorker$1.call(AbstractWorker.java:41)
18	at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
19	at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
20	at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
21	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
22	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
23	at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
24	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
25	at org.gradle.workers.internal.AbstractWorker.executeWrappedInBuildOperation(AbstractWorker.java:41)
26	at org.gradle.workers.internal.NoIsolationWorkerFactory$1.execute(NoIsolationWorkerFactory.java:56)
27	at org.gradle.workers.internal.DefaultWorkerExecutor$3.call(DefaultWorkerExecutor.java:215)
28	at org.gradle.workers.internal.DefaultWorkerExecutor$3.call(DefaultWorkerExecutor.java:210)
29	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
30	at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.runExecution(DefaultConditionalExecutionQueue.java:215)
31	at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.runBatch(DefaultConditionalExecutionQueue.java:164)
32	at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.run(DefaultConditionalExecutionQueue.java:131)
33	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
34	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
35	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
36	at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
37	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
38	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
39	at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
40	at java.lang.Thread.run(Thread.java:748)
41Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete
42	at com.android.tools.r8.utils.t.a(:55)
43	at com.android.tools.r8.D8.run(:11)
44	at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:116)
45	... 34 more
46Caused by: com.android.tools.r8.utils.AbortException: Error: Program type already present: io.flutter.BuildConfig
47	at com.android.tools.r8.utils.Reporter.a(:21)
48	at com.android.tools.r8.utils.Reporter.a(:7)
49	at com.android.tools.r8.utils.t.a(:36)
50	... 36 more
51
52
53FAILURE: Build failed with an exception.
54
55* What went wrong:
56Execution failed for task ':app:mergeExtDexDebug'.
57> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
58   > com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: 
59     Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.
60     Program type already present: io.flutter.BuildConfig
61
62* Try:
63Run 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.
64
65* Get more help at https://help.gradle.org
66
67BUILD FAILED in 15s
68[!] The shrinker may have failed to optimize the Java bytecode.
69To disable the shrinker, pass the `--no-shrink` flag to this command.
70To learn more, see: https://developer.android.com/studio/build/shrink-code
71Exception: Gradle task assembleDebug failed with exit code 1
72

参考にしている解決方法

下記のリンク先にある、７番 : The refactoring preview shows the list of changes. Finally, click Do Refactor:
この refactoring previewがどこに表示されてるかが明記されておらず、先に進めません。

リンク内容

補足情報（FW/ツールのバージョンなど）

先月にFlutter, Android共に最新版にしてから、エラーばかりで先に進めません。。。
MacOS Mojaveです。

satokei

2020/09/23 13:11

質問とは違いますが、、、 > D8: Program type already present: io.flutter.BuildConfig このエラーメッセージで検索すると以下ページがありました。 https://github.com/flutter/flutter/issues/40830 前提として以下は実行していますか？・flutter clean ・flutter pub get