Skip broadcasting to a receiver if the receiver seems to be dead

If an application that has a broadcast receiver is killed
during broadcasting, thread variable of ProcessRecord becomes null
so that IIntentReceiver#performReceive() is called
in BroadcastQueue#performReceiveLocked(). But if binder driver has not
noticed the death of the application yet, it can't throw
DeadObjectException. After that, binder driver notices. But it can't
notify DeadObjectException to the caller because performReceive() is
async call. So broadcasting keeps on waiting for finishing
performReceive() until timeout.

This change checks the death of the application before calling
performReceive() and skips broadcasting to the receiver
if the application has already died.

Change-Id: Ifa02b8b1a7e7b6fd314de90fedff5b7a5326825d