Bug 1480421 - Crash reporter not working prior to Android O r=jchen

Summary:
When running on pre Oreo devices CrashReportingService (a JobIntentService)
is started as a regular Service.
Return super.onStartCommand(..) to make sure onHandleWork() would be caled.

Reviewers: sdaswani, VladBaicu, jchen

Reviewed By: jchen

Bug #: 1480421

Differential Revision: https://phabricator.services.mozilla.com/D3102

--HG--
extra : rebase_source : 78d83fca65b000a10e2f8b522c8ee57cd364a829
extra : histedit_source : 71a48d23421fec60ded4c0c45c8cafb8927196ab

mobile/android/geckoview/src/main/java/org/mozilla/gecko/CrashReporterService.java

@@ -86,7 +86,7 @@ public class CrashReporterService extends JobIntentService {
             enqueueWork(this, intent);
         }
 
-        return Service.START_NOT_STICKY;
+        return super.onStartCommand(intent, flags, startId);
     }
 
     @Override