I am building my app with Flutter. Now I am always getting this error: 

```
FAILURE: Build failed with an exception.* What went wrong:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug',> 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: https://developer.android.com/tools/building/multidex.html* 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 32s Finished with error: Gradle build failed: 1

```

So this error clearly says that I must add multidex-support. But how to do this in FLUTTER?