Use the fact that a JobIntentService is still a Service to keep most of the
previous implementation and method of starting CrashReportingService.
On 26+ devices it will be called with "start-foreground-service".
This ensures it can be started even from background and the crash reporting
process would work as before but ActivityManager will post an ANR error to
logcat after 5 seconds because we aren't calling Service.startForeground()
(which would mean a user visible notification).

Will use different Job Ids depending on if the app is Firefox Release or
Firefox Beta.
The Job Id will be passed to GeckoThread when first initializing and then be
made available to CrashHandler and nsExceptionHandler.cpp to be sent in the
Intent that starts the CrashReporterService.

MozReview-Commit-ID: GATl6Waa9St

--HG--
extra : amend_source : 70bc130b9411df336181e825ebb3e19bdc5a778c