( cherry-pick of 00d6fa79f7 )
Specifying a runner allows developers to run commands like:
`runtest frameworks-services`
without getting a message like:
"Could not find instrumentation
com.android.frameworks.servicestests/android.test.InstrumentationTestRunner
on device."
Bug: 28833951
Change-Id: I76fb58a8fa16db503c8e98eb5a09c481d41e0a76
Test: Described above