chore: added enums

Author: pawan1210

modules/backend/metadata.display.yaml

@@ -77,6 +77,11 @@ spec:
         load_balancing_scheme:
           name: load_balancing_scheme
           title: Load Balancing Scheme
+          enumValueLabels:
+            - label: EXTERNAL_MANAGED
+              value: EXTERNAL_MANAGED
+            - label: INTERNAL_MANAGED
+              value: INTERNAL_MANAGED
         locality_lb_policy:
           name: locality_lb_policy
           title: Locality Lb Policy

modules/frontend/metadata.display.yaml

@@ -76,6 +76,13 @@ spec:
         load_balancing_scheme:
           name: load_balancing_scheme
           title: Load Balancing Scheme
+          enumValueLabels:
+            - label: EXTERNAL_MANAGED
+              value: EXTERNAL_MANAGED
+            - label: INTERNAL_MANAGED
+              value: INTERNAL_MANAGED
+            - label: INTERNAL_SELF_MANAGED
+              value: INTERNAL_SELF_MANAGED
         managed_ssl_certificate_domains:
           name: managed_ssl_certificate_domains
           title: Managed Ssl Certificate Domains