Create test utils and shims for porting AppSearch CTS tests.

The shims adapt the framework API to ListenableFuture so that the
jetpack tests can be reused.

Bug: 170997047
Bug: 162450968
Bug: 175661706
Test: CtsAppSearchTestCases
Change-Id: I649a94b784fb74af137788e3a08106296dcb57fb