Switch from using xtend to java in md-sal adapters

This is part of my effort to switch all xtend code in the adapters to java

Change-Id: I10c679fbe5f7980facd1b5e5d2e0a5c3ae997ff6
Signed-off-by: Moiz Raja <moraja@cisco.com>
Merge "Switch from using xtend to java in md-sal adapters"