[Android] Add a new API to simulate activity started on ApplicationStatusManager

When ApplicationStatus initialized after application started, the onActivityCreated(),
onActivityStarted() and onActivityResumed() callbacks will be missed.
This function will give the chance to simulate these three callbacks.

BUG=XWALK-1366
Merge pull request #142 from kurli/M35-fix-activity-status

[Android] Add a new API to simulate activity started on ApplicationStatu...