LocationPickerActivity.java: rewrite comments to clarify if statement

Before this change, a comment in showInMapApp did not properly describe an if statement's intended behavior.

After this change, the old comment was removed and 2 new comments were added in each part of the if statement
to properly describe the intended behavior.

Author: Jason-Whitmore

app/src/main/java/fr/free/nrw/commons/LocationPicker/LocationPickerActivity.java

@@ -402,11 +402,12 @@ private void removeLocationFromImage() {
     private void showInMapApp() {
         fr.free.nrw.commons.location.LatLng position = null;
 
-        //Check to see if EXIF location data is available
         if(activity.equals("UploadActivity") && cameraPosition != null){
+            //EXIF location data is available
             position = new fr.free.nrw.commons.location.LatLng(cameraPosition.getLatitude(),
                 cameraPosition.getLongitude(), 0.0f);
         } else if(mapView != null){
+            //EXIF location data is not available
             position = new fr.free.nrw.commons.location.LatLng(mapView.getMapCenter().getLatitude(),
                 mapView.getMapCenter().getLongitude(), 0.0f);
         }