feat: Adding connection to kms for pubsub topic (#288)

Author: anshukaira

metadata.yaml

@@ -202,6 +202,12 @@ spec:
       - name: topic_kms_key_name
         description: The resource name of the Cloud KMS CryptoKey to be used to protect access to messages published on this topic.
         varType: string
+        connections:
+          - source:
+              source: github.com/terraform-google-modules/terraform-google-kms
+              version: ">= 4.1.1"
+            spec:
+                outputExpr: key_id_list[0]
       - name: grant_bigquery_project_roles
         description: Specify true if you want to add bigquery.metadataViewer and bigquery.dataEditor roles to the default Pub/Sub SA.
         varType: bool