1. Skip tearDown for < S release.
2. Check installation of custom App rather than GMSCore.

For 1, We skip the test initially in the setup if the device is at a version
< S, hence none of the stuff is set up in that case. tearDown()
should behave in the same way.

For 2, GMSCore package is absent on GSI images. So, instead, install
a custom package and check for its presence.

Test: atest CtsAppCloningHostTest
Bug: 192209593
Bug: 187904310
Bug: 187904310
Bug: 192013761
Change-Id: I6f4eaa39c3b826df41ac7d5f826466366da2554f