Merge "Set up libtextclassifier_tests into MTS" into rvc-dev am: 0bce29a225

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

Change-Id: Ic83d9f8b196e014dad91e5fc076bf4927a6a706f