Revert "Revert "Switching to lazily batching alarms by default""

This reverts commit 5382b705.

Reason for revert: Broken test now fixed.

Test: atest CtsAlarmManagerTestCases
atest CtsAppTestCases:android.app.cts.AlarmManagerTest

Bug: 161497385
Change-Id: I37eb3096b50b95d5795adb418b3cb1c7cca48eb8