Simplified how AbstractRemoteService subclasses run an async request.

In these cases the request never times out, so it can be simplified by using
a lambda to represent the request.

Bug: 117779333
Test: atest CtsContentCaptureServiceTestCases CtsAutoFillServiceTestCases

Change-Id: Iba52aad1315ae7d3982671a0fdeabe87a6d6ee04