Need to add our Xts Media tests to the test package, so that we can
execute those tests with our nightly regression.
Bug: 22094009
Change-Id: I7e7ed8bf5f6edb905832495bea6347f97b6c5894
Inclusion depends on a subsequent cl in vendor/google,
referencing the WIDEVINE_TEST_MAKE_TARGETS variable within.
Subsequent cl: https://googleplex-android-review.git.corp.google.com/681048
Change-Id: Ibaad415213b193dfb55426e4a9d725e39f4c05b3