Watchdog: Improvement of debuggability

If the watchdog detects a problem the system server process
is killed, that is followed by a crash. Because the crash is
done after the system server process is killed, the crash
don't contain info about the system server.
This improvement will make sure that the system is crashed
before the system server process is killed.
Behavior is only changed for eng and userdebug builds.

Change-Id: I9f1c8fd8b03d0114032ed44fb582705ad0b49733