No. Obama merely quotes Auma as believing all other claims are contested. The person indicated by Auma as lacking documentation is Auma's mother.. Obama doesn't say one thing here about what HIS mother may have had or not had by way of documentation about Obama, or whether either Obama or Stanley Ann thought Obama's claim was contested.
You're reading into the text what isn't there.
What isn’t in the text is Obama’s correction of (according to you) the falsity of Auma’s statement.
Obama wrote, having his half-sister state, that only the children of Obama Sr-Ruth have an uncontested claim.
You are reading into the text what isn’t there, you are reading that Obama states his claim was uncontested.