Fix androidx.test bazel build by using public visibility in bazel and android.support library.
Fix androidx.test bazel build by using public visibility in bazel and android.support library.

Caveat: there is still an open issue when android-28 is used - wrt accessing android.test APIs.
PiperOrigin-RevId: 201013973

android/android-test,android/android-test,android/android-test,android/android-test,android/android-test