Merge branch 'stable-3.1' into stable-3.2

* stable-3.1:
  Use Gerrit 3.1.8 in Dockerfile
  Upgrade bazlets to latest stable-3.1 to build with 3.1.8 API
  Use Gerrit 3.0.12 in Dockerfile
  Upgrade bazlets to latest stable-3.0 to build with 3.0.12 API
  Use Gerrit 2.16.22 in Dockerfile
  Upgrade bazlets to latest stable-2.16 to build with 2.16.22 API

Change-Id: I00198b7e6c96e7237c1b4418941be4df643b6d5d
diff --git a/src/test/docker/gerrit/Dockerfile b/src/test/docker/gerrit/Dockerfile
index f7204b4..4a1dfbb 100644
--- a/src/test/docker/gerrit/Dockerfile
+++ b/src/test/docker/gerrit/Dockerfile
@@ -1,4 +1,4 @@
-FROM gerritcodereview/gerrit:3.1.7
+FROM gerritcodereview/gerrit:3.1.8
 
 ENV GERRIT_BRANCH=stable-3.1