Update mainline version for the 16 branch.

Change-Id: I4d36277d10335349d83ae218fa10fee99c3e4c14

.gitreview

@@ -1,5 +1,5 @@
 [gerrit]
-defaultbranch=master
+defaultbranch=16
 #
 # Intentional padding to ensure it is possible to point a commit
 # to an alternative gerrit server/repository without breaking

build_tools/make_version

@@ -3,7 +3,7 @@
 AWK=${AWK:-awk}
 GIT=${GIT:-git}
 GREP=${GREP:-grep}
-MAINLINE_BRANCH=master
+MAINLINE_BRANCH=16
 
 if [ -f ${1}/.version ]; then
     cat ${1}/.version