Build metrics-reporter-cloudwatch against stable-1{2,3,4}

Metrics-reporter-cloudwatch plugin master branch has been migrated to
bazelmod with change If3607f83, so it is no longer compatibile with
Gerrit stable-3.12. stable-3.13 and stable-3.14.

Change-Id: Iadcd1f137023ebc87c5d956f2c0b4c117418572d

jenkins/gerrit-bazel-plugin-metrics-reporter-cloudwatch.yaml

diff --git a/jenkins/gerrit-bazel-plugin-metrics-reporter-cloudwatch.yaml b/jenkins/gerrit-bazel-plugin-metrics-reporter-cloudwatch.yaml
index 9d9d8e6..c8a1e91 100644
--- a/jenkins/gerrit-bazel-plugin-metrics-reporter-cloudwatch.yaml
+++ b/jenkins/gerrit-bazel-plugin-metrics-reporter-cloudwatch.yaml
@@ -4,10 +4,6 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
-      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
-          branch:
-            - master
-          gerrit-branch:
             - stable-3.14
             - stable-3.13
             - stable-3.12