Also updates some related generics definitions for better/simpler compile-time checks. Bug: 178536734 Test: Manual Change-Id: If439b64ad968f62674f856fd3ff465bf21cc9204
Bug: 178536734 Test: Manually using implementation in SupportApp Change-Id: Ia1cfbbf2944ca5f92e9e7144076eb15878e164d1 Merged-In: Ia1cfbbf2944ca5f92e9e7144076eb15878e164d1