ProfileManagerService: Fix initialization order

According to the lifecycle of a SystemService, onStart() is called to get
the service running and the service should publish its binder interface
at that point. First of all, ensure to do that and then initialize the
rest of the stuff only during PHASE_ACTIVITY_MANAGER_READY boot phase,
because services can only broadcast intents after that phase.

This fixes a particular issue, that was causing LineageParts to crash
while starting System Profiles activity.

Change-Id: I8a397523aec8b5008da3e596eee23463618c8489