Refactor AdId / AppSetId getInstance() methods.

They don't take a context anymore, but rather use
ApplicationContextSingleton.get()

Test: atest AdServicesServiceCoreAdIdUnitTests AdServicesServiceCoreAppsetIdUnitTests AdServicesApkUnitTests:AppSetIdServiceTest AdExtServicesApkUnitTests:AppSetIdServiceTest

Bug: 311183933

Change-Id: I66fff266be94895182fca08a1e6b933c79dc2467
11 files changed