Android - Added a flag to disable external intent requests

According to https://codereview.chromium.org/71283003/ Chrome supports a command-line flag to disable external intent notifications (bot sure which versions but it doesn't appear to be supported in 31 - probably 32 or 33 based on the date).

This will make sure requested URLs open in Chrome and aren't opened in an external app and will also allow Chrome Stable and beta to be run on the same device.