【cordova】cordova-plugin-file-transferを使うと、Androidでファイル送信が0バイトになってしまう。

cordovaでcordova-plugin-file-transferを使って、
写真をサーバーへアップロードるするAndroidアプリを作成しています。

わたくしの後述のコードでは、下記のconsole logが出力されます。

Successful file write...
fileURL : file:///data/data/com.adobe.phonegap.app/cache/.Pic.jpg%3F1530809009472
Successful upload...
fileEntry.fullPath = /.Pic.jpg?1530809009472
Code = 200
response = 
bytesSent = 0

このログより、Androidからサーバーへのアクセスは成功しているようですが、
ファイルの転送が0バイト、つまり転送されていないようです。

また、サーバー側では、ファイルは保存されていますが
サイズが0バイトとなっていました。

どなたか、解決策が分かる方、ご回答よろしくお願い致します。

また、他に必要な情報がありましたら、ご指摘お願い致します。

バージョン：

Phonegap Buiid : 7.1.0
Android : 5.0.1
cordova-plugin-file : 6.0.1
cordova-plugin-file-transfer : 1.7.1

ソースコード：

//select and upload picture
$(document).on("click", ".pic-button", function() {
	openFilePicker();
});

function openFilePicker(selection) {
	var srcType = Camera.PictureSourceType.SAVEDPHOTOALBUM;
	var options = setOptions(srcType);

	if (selection == "picker-thmb") {
		// To downscale a selected image,
		// Camera.EncodingType (e.g., JPEG) must match the selected image type.
		options.targetHeight = 100;
		options.targetWidth = 100;
	}

	navigator.camera.getPicture(function cameraSuccess(imageUri) {

		// Do something with image
		console.log("get picture");
		console.log("imageUri : "+imageUri);

		image_uri = imageUri;
		URItoFileEntry(imageUri);
		onUploadFile(imageUri);

	}, function cameraError(error) {
		//console.debug("Unable to obtain picture: " + error, "app");
		console.log("Unable to obtain picture: " + error, "app");

	}, options);
}

function setOptions(srcType) {
	var options = {
		// Some common settings are 20, 50, and 100
		quality: 50,
		destinationType: Camera.DestinationType.FILE_URI,
		// In this app, dynamically set the picture source, Camera or photo gallery
		sourceType: srcType,
		encodingType: Camera.EncodingType.JPEG,
		mediaType: Camera.MediaType.PICTURE,
		allowEdit: true,
		correctOrientation: true  //Corrects Android orientation quirks
	}
	return options;
}

function URItoFileEntry(imageURI) {
	console.log("URItoFileEntry");
	window.resolveLocalFileSystemURL(imageURI, fileEntryToArrayBuffer, onError);
}

function fileEntryToArrayBuffer(fileEntry) {
	console.log("fileEntryToArrayBuffer");
	console.log(fileEntry.name);

	file_entry_name = image_uri.substr(image_uri.lastIndexOf('/') + 1);


	fileEntry.file( function(file) {
		console.log("fileEntry.file");

		var reader = new FileReader();

		reader.onloadend = ArrayBufferToBlob;

		reader.readAsArrayBuffer(file);

	}, onError2);
}

function ArrayBufferToBlob(event) {
	console.log("ArrayBufferToBlob");

	blob = new Blob([event.target.result], { type: "image/jpeg" });

	console.log("blob.size : "+blob.size);
	console.log("blob.type : "+blob.type);
}

function onError() {
	console.log("onError");
}

function onError2() {
	console.log("onError2");
}


function onUploadFile(imageUri) {
	console.log("onUploadFile");
	console.log("imageUri : "+imageUri);

	window.requestFileSystem(window.TEMPORARY, 5 * 1024 * 1024, function (fs) {

		console.log('file system open: ' + fs.name);
		var dirEntry = fs.root;

		console.log("imageUri : "+imageUri);

		dirEntry.getFile(imageUri, { create: true, exclusive: false }, function (fileEntry) {

			console.log("fileEntry name");
			console.log(fileEntry.name);

			// Write something to the file before uploading it.
			console.log("writeFile");
			writeFile(fileEntry);

		}, onErrorCreateFile);

	}, onErrorLoadFs);

	console.log("onUploadFile end");
}

function writeFile(fileEntry, dataObj) {
	// Create a FileWriter object for our FileEntry (log.txt).
	fileEntry.createWriter(function (fileWriter) {

		fileWriter.onwriteend = function () {
			console.log("Successful file write...");

			upload(fileEntry);
		};

		fileWriter.onerror = function (e) {
			console.log("Failed file write: " + e.toString());
			console.log(e.toString());
		};

		if (!dataObj) {
			if(blob == undefined) {
				console.log("blob undefined");
			} else {
				console.log("blob defined");

				dataObj = blob;
			}
		}

		fileWriter.write(dataObj);
	}, failCreateWriter);
}

function failCreateWriter(error) {
	console.log(error.code);
}

function upload(fileEntry) {
	// !! Assumes variable fileURL contains a valid URL to a text file on the device,
	var fileURL = fileEntry.toURL();

	var success = function (r) {
		console.log("Successful upload...");
		console.log("fileEntry.fullPath = " + fileEntry.fullPath);
		console.log("Code = " + r.responseCode);
		console.log("response = " + r.response);
		console.log("bytesSent = " + r.bytesSent);
	}

	var fail = function (error) {
		ons.notification.alert("An error has occurred: Code = " + error.code);
	}

	function displayFileData(data){
		console.log("displayFileData");
		//ons.notification.alert(data);
	}

	var options = new FileUploadOptions();
	options.chunkedMode = false;
	options.fileKey = "file";
	options.fileName = file_entry_name;
	options.mimeType = "image/jpeg";

	var params = {};
	params.value1 = "test";
	params.value2 = "param";

	options.params = params;

	console.log("fileURL : "+fileURL);

	var ft = new FileTransfer();
	// SERVER must be a URL that can handle the request, like
	// http://some.server.com/upload.php
	var url_post_image = "http://some.server.com/upload.php";
	ft.upload(fileURL, encodeURI(url_post_image), success, fail, options);
};

function onErrorLoadFs() {
	console.log("onErrorLoadFs");
}

function onErrorCreateFile() {
	console.log("onErrorCreateFile");
}