org.apache.conn.ssl: rename DistinguishedNameParser to AndroidDistinguishedNameParser

The name DistinguishedNameParser is used by other libraries having the
same package, and some apps incorrectly include packages that are
present in the boot classpath. This relatively newly introduced
DistinguishedNameParser ends up hiding the ones in the libraries.

Bug: 26647082
Change-Id: I735aef3c1e5dd04e5a8e2eda6da6d9c9179f1c70