Chore: Move stage jobs back to Centos7

Centos8 builder has issues with SIGUL
We need to fix those first or use a different node

Issue-ID: CIMAN-33
Signed-off-by: Jessica Wagantall <jwagantall@linuxfoundation.org>
Change-Id: I0ecf9aab3579611cf0de7841d3bef820b8baa601
diff --git a/jjb/aai/aai-graphadmin.yaml b/jjb/aai/aai-graphadmin.yaml
index 91c5755..593a6aa 100644
--- a/jjb/aai/aai-graphadmin.yaml
+++ b/jjb/aai/aai-graphadmin.yaml
@@ -13,7 +13,7 @@
       - '{project-name}-{stream}-merge-java'
       - gerrit-maven-stage:
           sign-artifacts: true
-          build-node: centos8-builder-4c-4g
+          build-node: centos7-builder-4c-4g
           maven-versions-plugin: true
           sbom-generator: true
       - gerrit-maven-docker-stage: