Enable extservices tests to generate android-mts-extservices as well as
android-mts.

Bug: 170318013
Test: built locally and verified contents.
Change-Id: I48e48bdee8957ebbd4c5c3db95854fc0a0cdb13d
Merged-In: I48e48bdee8957ebbd4c5c3db95854fc0a0cdb13d
Exempt-From-Owner-Approval: approved by owners in downstream branch.
3 files changed