Handle invalid data during job loading.

Catch exceptions that may be thrown if invalid data ended up in the
persisted job file.

Bug: 246541702
Bug: 246542132
Bug: 246542285
Bug: 246542330
Test: install test app with invalid job config, start app to schedule job, then reboot device
Change-Id: Id0ceba345942baf21177f687b8dd85ef001c0a9e