DO NOT MERGE: Keep old callback thread

Discrepency between documented and delivered thread in prior versions
got confused. Switching back to the main thread for delivery when not
specified.

Bug: 160565229
Test: presubmit only
Change-Id: I6deaf08e2045771c120aa2eb35c64b392208bd58

location/java/android/location/LocationManager.java

@@ -1951,7 +1951,8 @@ public class LocationManager {
         }
 
         try {
-            return mGnssStatusListenerManager.addListener(listener, Runnable::run);
+            return mGnssStatusListenerManager.addListener(listener,
+                    new HandlerExecutor(new Handler()));
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -2086,7 +2087,7 @@ public class LocationManager {
     @Deprecated
     @RequiresPermission(ACCESS_FINE_LOCATION)
     public boolean addNmeaListener(@NonNull OnNmeaMessageListener listener) {
-        return addNmeaListener(Runnable::run, listener);
+        return addNmeaListener(listener, null);
     }
 
     /**