Support Android url scheme and event APP_OPENED_FROM_URL

This adds the event APP_OPENED_FROM_URL to the android host as well. Very useful for deep-linking. We are using this in our host, but it presents one problem:

The code included here in the pull request will only trigger the event if the app is already running. As this very often is not the case, we hacked around it by triggering the event a little bit delayed in the onResume function. If anyone with android skills and knowledge have a good solution to this, that would make the pull request more complete.