Merge "Set up libtextclassifier_tests into MTS" into rvc-dev am: 0bce29a225 am: 0cc49dfcad am: 68d4086add

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

Change-Id: I2069b09f35437da9ec00db271fdccc4ce3f92b4e