Refactor and readd unnecessary id

Signed-off-by: Joris Bodin <joris.bodin@infomaniak.com>

src/main/java/com/owncloud/android/ui/activity/SyncedFoldersActivity.java

@@ -232,6 +232,7 @@ public class SyncedFoldersActivity extends FileActivity implements SyncedFolderA
 
     private void showPowerCheckDialog() {
         AlertDialog alertDialog = new AlertDialog.Builder(this)
+            .setView(findViewById(R.id.root_layout))
             .setPositiveButton(R.string.common_ok, (dialog, which) -> dialog.dismiss())
             .setTitle(ThemeUtils.getColoredTitle(getResources().getString(R.string.autoupload_disable_power_save_check),
                                                  ThemeUtils.primaryAccentColor(this)))

src/main/java/com/owncloud/android/utils/DisplayUtils.java

@@ -750,7 +750,6 @@ public final class DisplayUtils {
         FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
         fragmentTransaction.addToBackStack(null);
 
-        SortingOrderDialogFragment mSortingOrderDialogFragment = SortingOrderDialogFragment.newInstance(sortOrder);
-        mSortingOrderDialogFragment.show(fragmentTransaction, SORTING_ORDER_FRAGMENT);
+        SortingOrderDialogFragment.newInstance(sortOrder).show(fragmentTransaction, SORTING_ORDER_FRAGMENT);
     }
 }

src/main/res/layout/files.xml

@@ -27,6 +27,7 @@
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
+        android:id="@+id/root_layout"
         android:orientation="vertical">
 
             <include layout="@layout/toolbar_standard" />