Sort readonly plugin branches in reverse ordering

Reorder the branch names from the most recent to
the oldest one, like all the other YAML files.

Change-Id: Idf57d093a9c0c3a7fe446cf85194168122962ab7
diff --git a/jenkins/gerrit-bazel-plugin-readonly.yaml b/jenkins/gerrit-bazel-plugin-readonly.yaml
index e046bdc..96c2a2c 100644
--- a/jenkins/gerrit-bazel-plugin-readonly.yaml
+++ b/jenkins/gerrit-bazel-plugin-readonly.yaml
@@ -5,8 +5,8 @@
           branch:
             - master
           gerrit-branch:
-            - stable-3.10
             - stable-3.11
+            - stable-3.10
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master