ExploreMapFragment.java: fix performMapReadyActions to center to user's last known location

Before this commit, fixing a previous bug caused performMapReadyActions to center the map
on a default location rather than the available last known location.

This commit adds code which will attempt to get the last known user location. If it cannot
be retrieved, the default location is used. The map now centers properly.

app/src/main/java/fr/free/nrw/commons/ViewPagerAdapter.java

@@ -18,6 +18,17 @@ public class ViewPagerAdapter extends FragmentPagerAdapter {
         super(manager);
     }
 
+    /**
+     * Constructs a ViewPagerAdapter with a specified Fragment Manager and Fragment resume behavior.
+     *
+     * @param manager The FragmentManager
+     * @param behavior An integer which represents the behavior of non visible fragments. See
+     *                 FragmentPagerAdapter.java for options.
+     */
+    public ViewPagerAdapter(FragmentManager manager, int behavior) {
+        super(manager, behavior);
+    }
+
     /**
      * This method returns the fragment of the viewpager at a particular position
      * @param position

app/src/main/java/fr/free/nrw/commons/explore/ExploreFragment.java

@@ -12,6 +12,7 @@ import android.view.ViewGroup;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentPagerAdapter;
 import androidx.viewpager.widget.ViewPager.OnPageChangeListener;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.ViewPagerAdapter;
@@ -69,7 +70,9 @@ public class ExploreFragment extends CommonsDaggerSupportFragment {
         loadNearbyMapData();
         binding = FragmentExploreBinding.inflate(inflater, container, false);
 
-        viewPagerAdapter = new ViewPagerAdapter(getChildFragmentManager());
+        viewPagerAdapter = new ViewPagerAdapter(getChildFragmentManager(),
+            FragmentPagerAdapter.BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
+
         binding.viewPager.setAdapter(viewPagerAdapter);
         binding.viewPager.setId(R.id.viewPager);
         binding.tabLayout.setupWithViewPager(binding.viewPager);

app/src/main/java/fr/free/nrw/commons/explore/map/ExploreMapFragment.java

@@ -221,7 +221,6 @@ public class ExploreMapFragment extends CommonsDaggerSupportFragment
             binding.mapView.getController().setZoom(ZOOM_LEVEL);
         }
 
-        performMapReadyActions();
 
         binding.mapView.getOverlays().add(new MapEventsOverlay(new MapEventsReceiver() {
             @Override
@@ -341,7 +340,12 @@ public class ExploreMapFragment extends CommonsDaggerSupportFragment
             !locationPermissionsHelper.checkLocationPermission(getActivity())) {
             isPermissionDenied = true;
         }
+
+        lastKnownLocation = getLastLocation();
+
+        if (lastKnownLocation == null) {
             lastKnownLocation = MapUtils.getDefaultLatLng();
+        }
 
         // if we came from 'Show in Explore' in Nearby, load Nearby map center and zoom
         if (isCameFromNearbyMap()) {
@@ -962,9 +966,6 @@ public class ExploreMapFragment extends CommonsDaggerSupportFragment
                     -0.07483536015053005, 1f);
             }
         }
-        if (!isCameFromNearbyMap()) {
-            moveCameraToPosition(new GeoPoint(latLnge.getLatitude(), latLnge.getLongitude()));
-        }
         return latLnge;
     }