[SPARK-17742][CORE] Fail launcher app handle if child process exits with error.

This is a follow up to cba826d0; that commit set the app handle state
to "LOST" when the child process exited, but that can be ambiguous. This
change sets the state to "FAILED" if the exit code was non-zero and
the handle state wasn't a failure state, or "LOST" if the exit status
was zero.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #19012 from vanzin/SPARK-17742.