Get cluster_id from kubernetes_resource for CIS

This change fetches the cluster_id from
kubernetes_resource object as per the schema.

EE: true
Changelog: changed

ee/lib/gitlab/ci/parsers/security/cluster_image_scanning.rb

@@ -10,7 +10,7 @@ module Gitlab
           def create_location(location_data)
             ::Gitlab::Ci::Reports::Security::Locations::ClusterImageScanning.new(
               image: location_data['image'],
-              cluster_id: location_data['cluster_id'],
+              cluster_id: location_data.dig('kubernetes_resource', 'cluster_id'),
               operating_system: location_data['operating_system'],
               package_name: location_data.dig('dependency', 'package', 'name'),
               package_version: location_data.dig('dependency', 'version'))

ee/spec/fixtures/security_reports/master/gl-cluster-image-scanning-report.json

@@ -22,7 +22,13 @@
         },
         "operating_system": "debian:9",
         "image": "registry.gitlab.com/gitlab-org/security-products/dast/webgoat-8.0@sha256:bc09fe2e0721dfaeee79364115aeedf2174cce0947b9ae5fe7c33312ee019a4e",
-        "cluster_id": "1"
+        "kubernetes_resource": {
+          "namespace":"default",
+          "name":"sample-app",
+          "kind":"ReplicaSet",
+          "container_name":"webgoat",
+          "cluster_id":"1"
+        }
       },
       "identifiers": [
         {
@@ -59,7 +65,13 @@
         },
         "operating_system": "debian:9",
         "image": "registry.gitlab.com/gitlab-org/security-products/dast/webgoat-8.0@sha256:bc09fe2e0721dfaeee79364115aeedf2174cce0947b9ae5fe7c33312ee019a4e",
-        "cluster_id": "1"
+        "kubernetes_resource": {
+          "namespace":"default",
+          "name":"sample-app",
+          "kind":"ReplicaSet",
+          "container_name":"webgoat",
+          "cluster_id":"1"
+        }
       },
       "identifiers": [
         {