[UI] revert index.html base url and provide USE_AWS_INSTANCE_PROFILE example (#2403)

* revert index.html base url and provide USE_AWS_INSTANCE_PROFILE example

ui/manifests/deployment.yaml

@@ -101,3 +101,5 @@ spec:
             #       key: AWS_DEFAULT_REGION
             # - name: SPILO_S3_BACKUP_BUCKET
             #   value: <s3 bucket used by the operator>
+            # - name: "USE_AWS_INSTANCE_PROFILE"
+            #   value: "true"

ui/manifests/ingress.yaml

@@ -12,7 +12,7 @@ spec:
       http:
         paths:
           - path: /
-            pathType: ImplementationSpecific
+            pathType: Prefix
             backend:
               service:
                 name: "postgres-operator-ui"