[ActivityManager] Distinguish FG or BG receiver finished

Symptom:
Assume a foreground broadcast FG and a background BG.
If a recevier registers both FG and BG. When sending
BG and FG to the receiver, and the receiver BG receiver
completes first, its finishReceiver will trigger next FG
receiver rather than BG, and also deliver wrong result
code/data to the next.

More detail and sample:
https://code.google.com/p/android/issues/detail?id=92917

Root cause:
Due to BroadcastQueue:getMatchingOrderedReceiver will match
by receiver(IBinder), so the caller ActivityManagerService:
broadcastRecordForReceiverLocked will always match the first
queue(fg) if a receiver is both receiving fg and bg.

Solution:
Add a parameter flags to finishReceiver, then server side
could know the finished receiver should belong to which queue.

Another general solution but with bigger scope:
I60dce4a48e20c1002a61a979e4d78b9b0a8b94a0

Change-Id: I913ca6f101ac8ec6c7a8e42754e6781f80247b7f