You can't use that method to format to your desired string format. You would have to use a different method or reformat the string after you obtained the value.
This example uses regular expression to replace pattern with desired format:
CharSequence dd = DateUtils.
getRelativeDateTimeString(this, created,
DateUtils.MINUTE_IN_MILLIS, DateUtils.WEEK_IN_MILLIS,
DateUtils.FORMAT_ABBREV_MONTH
);
Log.i(TAG, dd.toString()
.replaceAll("^(\\d{1,2})/(\\d{1,2})/(\\d{4})", "$2.$1.$3")); // yyyyy.MMMMM.dd, hh:mm aaa