Remove standby delay from AlarmManager in favor of quotas.

We're moving forward with the quota system, and so no longer need to
keep the delay code or tests.

Bug: 142569967
Test: atest com.android.server.AlarmManagerServiceTest
Test: atest com.android.server.AppStateTrackerTest
Test: atest AppStandbyControllerTests
Test: atest CtsAlarmManagerTestCases
Change-Id: I9ce96a6e050f8dcd14d02fd707c8f4693e397ac5