Build optimizations to significantly reduce APK size

~~There are no FTC-legal `armeabi-v7a` (aka `arm32`) devices~~, and EasyOpenCV has supported `arm64-v8a` just fine for years now. Disabling the build of `armeabi-v7a` on SDK 10.3 cuts the APK size from ~48.8MB to ~40.3MB.

~~To disable `armeabi-v7a`, just replace both instances of `abiFilters "armeabi-v7a", "arm64-v8a"` with `abiFilters "arm64-v8a"` in [build.common.gradle](https://github.com/FIRST-Tech-Challenge/FtcRobotController/blob/master/build.common.gradle).~~

EDIT: See https://github.com/FIRST-Tech-Challenge/FtcRobotController/issues/797#issuecomment-3232804195 for the proper way to make the APKs smaller without breaking the SDK for teams using older RC phones.