Case Sensitive URL Check Prevents Successful Redirect with `openAuth` on Android

[Ariflo]

Issue

The check for event.url.startsWith(returnUrl) here prevented my OAuth session from successfully completing the redirect on Android. As far as I can tell this was due to the fact that we were passing in the app scheme URL in camel case as a redirect. In other words; "AwseomApp://" !== "awesomeapp://".

Suggested fix

Use .toLowerCase() to do a valid equivalent check here.