MediaShareActivity.getFilesForImageUriList: Rename idList to idListBuilder
MediaShareActivity.getFilesForImageUriList: Create String variable idList to hold results of idListBuilder.toString
MediaShareActivity: From getFilesForImageUriList, move code for constructing ID list string to a spearate method constructIdListString
MediaShareActivity.constructIdListString: Make idListBuilder final
MediaShareActivity: Add javadoc for getFilesForImageUriList
MediaShareActivity.getFilesForImageUriList: Correct documentation in comments
MediaShareActivity: Remove unused method getFileForImageURI