implement LocationManager and orientation sensor using libportal

src/api-impl/android/location/LocationManager.java

@@ -0,0 +1,31 @@
+package android.location;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class LocationManager {
+
+	static Set<LocationListener> listeners = new HashSet<>();
+
+	public String getBestProvider(Criteria criteria, boolean enabledOnly) {
+		return "xdgportal";
+	}
+
+	public Location getLastKnownLocation(String provider) {
+		return null;
+	}
+
+	public void requestLocationUpdates (String provider, long minTimeMs, float minDistanceM, LocationListener listener) {
+		listeners.add(listener);
+		nativeGetLocation();
+	}
+
+	private native void nativeGetLocation();
+
+	private static void locationUpdated(double latitude, double longitude, double heading) {
+		for (LocationListener locationListener : listeners) {
+			locationListener.onLocationChanged(new Location(latitude, longitude, heading));
+		}
+	}
+	
+}