Add ISystemSuspendCallback.

The callback will be used to synchronously report system suspend events.

Current usage: BatteryStatsService needs to be notified about
each system suspend attempt and whether it was successful.

Bug: 78888165
Test: SystemSuspendV1_0UnitTest
Change-Id: I234f74f6f3c35e5d6bb33ceda569e11520850ccf
7 files changed