Currently, sometimes the Proc.kill run on the emulator process will fail if the emulator process is hung really hard.
The process will not respond to SIGTERM, but will respond to SIGKILL - so we should kill it with that when we fail to SIGTERM it. Otherwise, the android emulator will think the AVD data is no longer in use, and cause weird errors when running new ones.

I filed JENKINS-11995 to track the required core change.