Update 2.16.6 release notes
Update 2.16.6 release notes

Change-Id: Ifd0baffeeabb2e799c5c1e1d4ee8ac07253da2e5

GerritCodeReview/homepage,GerritCodeReview/homepage,GerritCodeReview/homepage,GerritCodeReview/homepage,GerritCodeReview/homepage