Merge "Set up libtextclassifier_tests into MTS" into rvc-dev am: 0bce29a225 am: be3c7b5e56 am: cb282190bc am: 79e8f8c72b

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libtextclassifier/+/11685296

Change-Id: Ic900aa9347d84b3d2af3bf520c16564bf1fd030d