Build imagare plugin for 3.0, 3.1 and 3.2

Change-Id: I550940363ea4e77494e35543f0e9b9aa2bb2e234
diff --git a/jenkins/gerrit-bazel-plugin-imagare.yaml b/jenkins/gerrit-bazel-plugin-imagare.yaml
index 722c09a..4266139 100644
--- a/jenkins/gerrit-bazel-plugin-imagare.yaml
+++ b/jenkins/gerrit-bazel-plugin-imagare.yaml
@@ -4,4 +4,7 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
+            - stable-3.2
+            - stable-3.1
+            - stable-3.0
             - stable-2.16