If an application calls System.exit() terminate it immediately.

There is no graceful way to kill Android application processes.
They typically have many threads running doing various things
When System.exit() is called, those threads just keep going
while the cleanup actions run until the process finally.

Performing shutdown actions can easily cause more harm than good.
For example, closing the Binder driver's file descriptor may
cause other threads waiting on Binder to wake up and then crash
in nasty ways after receiving EBADF.

So when an Android application exits, skip the cleanup and just
call _exit() to end it all.

Bug: 6168809
Change-Id: I29790c064426a0bf7dae7cdf444eea3eef1d5275