Add protected broadcast for PO and DO provisioning

Added two protected broadcasts used to communicate
between DevicePolicyManagerService and ManagedProvisioning
during PO and DO provisioning.
They are used to notify MP to take a snapshot of the current
system apps, this snapshot is needed for the OTA logic.

Bug: 176973247
Bug: 175392542
Test: N/A
Change-Id: Ic9562ba8f5c684efb7c6ff292dcf5645d849e4d7