Retire preliminary FGS deferral control API

Now that we've settled the final API for this mechanism, retire the
preliminary one.

Bug: 186475652
Test: atest CtsAppTestCases:ServiceTest
Test: atest CtsAppTestCases:NotificationManagerTest
Change-Id: Ibe911627ad59b991f2e498689f7fa3019c19dc36
2 files changed