Add lastProcStateSeqDispatchedToObservers to UidRecord.

This will help in identifying the last procStateSeq for which AMS
notified NPMS about the process state change.

Bug: 27803922
Test: runtest -c com.android.server.am.ActivityManagerServiceTest frameworks-services

Change-Id: I741a8ffe31de92070f3ebbc9c4f95fc1c0a340cd
4 files changed