Timeout and discard process start requests exceeding a few minutes.

If AMS doesn't inform BroadcastQueue of process start/cleanup for any
reason, discard the process start request after a while instead of
letting it block the entire queue.

Also, expand the health checks with more logs to identify cases that
could be leading to unfulfilled process start requests.

Bug: 393898613
Test: atest services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueTest.java
Test: atest services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueImplTest.java
Flag: EXEMPT bugfix
Change-Id: Ia8d7143a1df7444a3df5255258d1b34e8962c4a2