This resolves#5523
While bumping `com.android.tools.build:gradle:3.1.2` to `3.3.0`, some other plugins/artifacts/maven repo/buildscripts have to be updated:
- gradle (wrapper) need to upgrade to 4.10.x
- protobuf gradle plugin need to bump a version compatible with gradle version.
- need add `google()` and `jcenter()` repos for android (otherwise `com.android.tools.build:aapt2:3.3.0x` and `trove4j` will not be found resp.)
- need to accept license for Android "build-tools;28.0.3" in kokoro env.
- add CI for kotlin non-android
- bump kotlin version to fix kotlin compiler issue on jdk11
- add javax.annotation dep to fix kotlin build on jdk 9 & 11
Fixes#4725