[ActivityManager] Fix process record leakage.

Symptom:
Remain dead process record in mLruProcesses.

Root cause:
When a process dies and needs to restart immediately.
The process record will not be removed from mLruProcesses
in handleAppDiedLocked (return kept=true).
If the restarting process start timeout, the record in
mLruProcesses will not be removed.

Solution:
Call removeLruProcessLocked in processStartTimedOutLocked.

Change-Id: I1935ccc586016cb4e90dfdfac96cc88931553d5f