CB-5988 android: Allow exec() only from file: or start-up URL's domain

Native side of change:
http://git-wip-us.apache.org/repos/asf/cordova-android/commit/aab47bd4
android: Delete Location-change JS->Native bridge mode

It was always disabled, and there's really no reason to keep it around.
Merge remote-tracking branch 'upstream/master'