Remove Gradle Warnings: Could not find google-services.json

This appears to be fixed with com.google.gms:google-services:4.0.2 which was released on July 13, 2018.

Gradle output with google-services:4.0.2:

> Configure project :app

> Task :app:processDebugGoogleServices
Parsing json file: /.../build/app/google-services.json

> Task :app:processReleaseGoogleServices
Parsing json file: /.../build/app/google-services.json

Gradle output with google-services:4.0.1:

> Configure project :app
Could not find google-services.json while looking in [src/nullnull/debug, src/debug/nullnull, src/nullnull, src/debug, src/nullnullDebug]
Could not find google-services.json while looking in [src/nullnull/release, src/release/nullnull, src/nullnull, src/release, src/nullnullRelease]

> Task :app:processDebugGoogleServices
Parsing json file: /.../build/app/google-services.json

> Task :app:processReleaseGoogleServices
Parsing json file: /.../build/app/google-services.json

It's a known regression. Check Google Issue #110321069 for details. Until a fix is provided, it's safe to just ignore the warning.

This is a bug with the Google Services gradle plugin. I've created a public bug report here: https://issuetracker.google.com/issues/110321069

If you want to work around the issue and hide the warnings, you can copy your google-service.json into app/src/debug and app/src/release.