Android: Update "Ti.Android.Service" to handle "FOREGROUND_SERVICE" permission

Apps targeting Android P must add a new FOREGROUND_SERVICE permission to the "AndroidManifest.xml" or else calling Ti.Android.Service.foregroundNotify() will throw a Java SecurityException internally and fail to start.
https://developer.android.com/preview/behavior-changes#fg-svc

We need to do the following:

• Log an error if the permission is missing when calling Service.foregroundNotify().
• Document that that this permission is required.