[Android] Add a new listener to listen the first rendered frame

To support the feature of launch screen. Added a new listener FirstRenderedFrameListener.
This listener will be triggered when the first visible content has been updated to the screen.

SPEC: https://docs.google.com/a/intel.com/document/d/17PuNuHRTQuREUpaCvj-eEx7uYi2avd-VW-oaMXMpvwo/edit?pli=1#
Design Doc: https://docs.google.com/a/intel.com/document/d/1YLajlZC7CkBOtEvzD6p6yeBr0HrPsaIGX8Eqhr3oTF4/edit#heading=h.mfsu3bk9566e
Bug: XWALK-637
Merge pull request #108 from kurli/launchScreen

[Android] Add a listener to listen when the view has been updated