Replaced primary color by element color for chosen Sort-By element

Signed-off-by: Kilian Périsset <kilian.perisset@infomaniak.com>

src/main/java/com/owncloud/android/ui/dialog/SortingOrderDialogFragment.java

@@ -130,7 +130,7 @@ public class SortingOrderDialogFragment extends DialogFragment {
      * tints the icon reflecting the actual sorting choice in the apps primary color.
      */
     private void setupActiveOrderSelection() {
-        final int color = ThemeUtils.primaryAccentColor(getContext());
+        final int color = ThemeUtils.elementColor(getContext());
         for (View view: mTaggedViews) {
             if (!((FileSortOrder) view.getTag()).name.equals(mCurrentSortOrderName)) {
                 continue;

src/main/res/values-night/colors.xml

@@ -36,6 +36,7 @@
     <color name="selected_item_background">#373535</color>
 
     <color name="filelist_icon_background">#222222</color>
+    <color name="standard_grey">#DADADA</color>
 
     <color name="drawer_menu_icon">#ffffff</color>
     <color name="bg_fallback_highlight">#737373</color>