Add force-stop subcommand for 'am'.

It's useful for some testing and debugging, to ensure all processes
are stopped before testing. 'kill' doesn't always work because sometimes the
system will restart the process immediately (e.g. if an app is running in
background).

Change-Id: I2c0caa38f74ee65ad6c35172fbf505227be7e7c3
1 file changed