* What went wrong:
Execution failed for task ':app:mergeDexDebug'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
> com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives:
The number of method references in a .dex file cannot exceed 64K.
Learn how to resolve this issue at https://developer.android.com/tools/building/multidex.html
解決方案在build.gradel 設置