Fix some javadoc issues

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

@@ -283,7 +283,7 @@ public class MediaDataExtractor {
     /**
      * Take our metadata and inject it into a live Media object.
      * Media object might contain stale or cached data, or emptiness.
-     * @param media
+     * @param media Media object to inject into
      */
     public void fill(Media media) {
         if (!fetched) {

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

@@ -65,7 +65,7 @@ public class Utils {
     /**
      * Capitalizes the first character of a string.
      *
-     * @param string
+     * @param string String to alter
      * @return string with capitalized first character
      */
     public static String capitalize(String string) {

app/src/main/java/fr/free/nrw/commons/location/LatLng.java

@@ -38,7 +38,7 @@ public class LatLng {
     /**
      * gets the latitude and longitude of a given non-null location
      * @param location the non-null location of the user
-     * @return
+     * @return A new instance of the class
      */
     public static LatLng from(@NonNull Location location) {
         return new LatLng(location.getLatitude(), location.getLongitude(), location.getAccuracy());

app/src/main/java/fr/free/nrw/commons/nearby/NearbyActivity.java

@@ -259,7 +259,7 @@ public class NearbyActivity extends NavigationBaseActivity implements LocationUp
     /**
      * This method should be the single point to load/refresh nearby places
      *
-     * @param isHardRefresh
+     * @param isHardRefresh Should display a toast if the location hasn't changed
      */
     private void refreshView(boolean isHardRefresh) {
         if (lockNearbyView) {

app/src/main/java/fr/free/nrw/commons/ui/widget/OverlayDialog.java

@@ -19,7 +19,7 @@ public abstract class OverlayDialog extends DialogFragment {
 
     /**
      * creates a DialogFragment with the correct style and theme
-     * @param savedInstanceState
+     * @param savedInstanceState bundle re-constructed from a previous saved state
      */
     @Override
     public void onCreate(Bundle savedInstanceState) {