We have the OkHttp server these days, so we don't need to use Netty. Use
the generic API instead of hard-coding OkHttp.
We've seen some recent interop failures. We aren't entirely sure what is
going on, but we have seen some Netty usages in logcat. Since we don't
even want Netty on Android, just get rid of it and even if it doesn't
help with the failures things are better dependency-wise.
Allows using Android's LocalSocket via a Socket adapter. Such an adapter
isn't generally 100% safe, since some methods may not have any effect,
but we know what methods are called by gRPC's okhttp transport and can
update the adapter or the transport as appropriate.
This is the latest version of the plugin supported by the Gradle version
in use at the moment (7.6).
Note that this also upgrades the R8 optimizer to a version (4.0.48) that
now uses "full mode" optimization by default.
This also splits off Android projects to run under Java 11 (Gradle
plugin requirement) while the other projects continue to run under Java
8.
Android Studio gives warning: "The minSdk version should not be declared in the android manifest file". Typically minSdkVersion should be configured in build.gradle, it was set in manifest since internally we use Blaze. cl/316513856 is created to update the internal BUILD file that configures minSdkVersion.