Made AbstractRemoteService.getRemoteRequestMillis() optional.

Also split some logic from PendingRequest into BasePendingRequest, so they're
not leaked into the async requests.

Test: atest CtsContentCaptureServiceTestCases CtsAutoFillServiceTestCases
Bug: 117779333
Change-Id: Ife9a3ab3a817944408caf9eae69dd75f48ab90c6
5 files changed