utiltests: add script to run tests

Make it easier to run the tests, so that more people
will run them.

Bug: 36698401
Test: tests/utiltests/runtests.sh \
      -e class com.android.internal.util.StateMachineTest

Change-Id: I3151fb6b2f609f45c7d8154b51f13cce58ccdc13
1 file changed