v1.39.2 CORE-1768 Add 'handleATTAuthorizationStatus' method to monitor ATT prompt performance.

Pass the AppTrackingTransparency authorization status from the callback of ATTrackingManager.requestTrackingAuthorization. Before prompting the user, check that ATTrackingManager.trackingAuthorizationStatus is notDetermined.

Swift sample code, note this should be called from the main thread:

if (ATTrackingManager.trackingAuthorizationStatus == .notDetermined) {
	ATTrackingManager.requestTrackingAuthorization { (status) in
		Branch.getInstance().handleATTAuthorizationStatus(status.rawValue)
	}
}