BUG: 17322886 bindService() to an invalid service might never actually result in onServiceConnected being called , for e.g. if the client service doesn't actually implement JobService. This wastes an execution slot as we end up waiting forever. Also made the javadocs clearer for the JobScheduler class. Change-Id: Ie15ebbe18c0b7579f2ab77dd46428d354ef632c3