use String.format(getString(format), ...) instead of buggy getString(format, ...)

Author: maxme

WordPressUtils/src/main/java/org/wordpress/android/util/StringUtils.java

@@ -316,6 +316,6 @@ public static String getQuantityString(Context context, @StringRes int zero, @St
         if (count == 1) {
             return context.getString(one);
         }
-        return context.getString(other, count);
+        return String.format(context.getString(other), count);
     }
 }