Merge changes I2ddef3ec,I70db2336 into stable-3.1

* changes:
  Explain how to set index.numStripedLocks
  Document last index update timestamp storage
diff --git a/WORKSPACE b/WORKSPACE
index 99f0dd0..2cbe3be 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "91ea277efd6d9f24c18d6ddeba65bed866b00872",
+    commit = "20079f696c22c733053077b13c0dc6d9902e6b8e",
     #local_path = "/home/<user>/projects/bazlets",
 )
 
diff --git a/src/test/docker/gerrit/Dockerfile b/src/test/docker/gerrit/Dockerfile
index 4a1dfbb..002ef9c 100644
--- a/src/test/docker/gerrit/Dockerfile
+++ b/src/test/docker/gerrit/Dockerfile
@@ -1,4 +1,4 @@
-FROM gerritcodereview/gerrit:3.1.8
+FROM gerritcodereview/gerrit:3.1.11
 
 ENV GERRIT_BRANCH=stable-3.1