In Android Marshmallow, permissions should be requested at runtime when they are needed, instead of all at once when an app is installed. However, I can only seem to request permissions from an Activity, which is a problem since my app contains only Services. (Why is that, you might ask? The app has an Android Wear watch face bundled inside, and all the phone does is look up photos nearby to send to the watch - no Activity needed. But it does require location permissions.)
So, is there any way to request permissions from a Service? Or somehow force the permissions to be granted at install time as in the past?