GONRG-5062: refactore anthos pipeline

devops/gcp/pipeline/override-stages.yml

+variables:
+  OSDU_GCP_SERVICE: legal
+  OSDU_GCP_VENDOR: gcp
+  OSDU_GCP_HELM_CONFIG_SERVICE_VARS: >
+    --set data.googleAudiences=$GOOGLE_AUDIENCE
+    --set data.logLevel=INFO
+  OSDU_GCP_HELM_CONFIG_SERVICE_VARS_DEV2: >
+    --set data.googleAudiences=$GOOGLE_AUDIENCE
+    --set data.logLevel=INFO
+  OSDU_GCP_HELM_DEPLOYMENT_SERVICE_VARS: >
+    --set data.image=$CI_REGISTRY_IMAGE/osdu-gcp-$OSDU_GCP_SERVICE:$CI_COMMIT_SHORT_SHA
+    --set data.serviceAccountName=$OSDU_GCP_SERVICE-k8s
+  OSDU_GCP_HELM_CONFIG_SERVICE: legal-config
+  OSDU_GCP_HELM_DEPLOYMENT_SERVICE: legal-deploy
+  OSDU_GCP_HELM_PACKAGE_CHARTS: "devops/gcp/deploy devops/gcp/configmap"