chat issue

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:preDebugBuild'.
> Android dependency 'com.android.support:support-fragment' has different version for the compile (26.1.0) and runtime (27.1.1) classpath. You should manually set the same version via DependencyResolution
>While we changing the version 'com.android.support.-v4 ' is comming in flutter