message: Add --fat_apk_cpu=arm64-v8a for arm64 Android builds
  Bazel silently uses the wrong build settings for --config=android_arm64 (--cpu=arm64-v8a is not enough), and actually still uses armeabi-v7a in at least some cases. --fat_apk_cpu fixes this.
  See for more.
diff: -# Android configs
  +# Android configs. Bazel needs to have --cpu and --fat_apk_cpu both set to the
  +# target CPU to build transient dependencies correctly. See
  +# https://docs.bazel.build/versions/master/user-manual.html#flag--fat_apk_cpu
  build:android --crosstool_top=//external:android/crosstool
  build:android --host_crosstool_top=@bazel_tools//tools/cpp:toolchain
  build:android_arm --config=android
  build:android_arm --cpu=armeabi-v7a
  +build:android_arm --fat_apk_cpu=armeabi-v7a
  build:android_arm64 --config=android
  build:android_arm64 --cpu=arm64-v8a
  +build:android_arm64 --fat_apk_cpu=arm64-v8a
  # Config to use a mostly-static build and disable modular op registration
  # support (this will revert to loading TensorFlow with RTLD_GLOBAL in Python).
  