Fix policies drawer header height for list page

- the drawer on the policies list page does not have
  the correct header height
- update the policy_drawer component to be configuraable
  for any header height

ee/app/assets/javascripts/threat_monitoring/components/constants.js

@@ -40,3 +40,5 @@ export const POLICY_TYPE_OPTIONS = {
     text: s__('SecurityPolicies|All policies'),
   },
 };
+
+export const POLICIES_LIST_CONTAINER_CLASS = '.js-security-policies-container-wrapper';

ee/app/assets/javascripts/threat_monitoring/components/policy_drawer/policy_drawer.vue

 <script>
 import { GlButton, GlDrawer } from '@gitlab/ui';
 import { getContentWrapperHeight, getPolicyKind } from '../../utils';
-import { POLICY_KINDS } from '../constants';
+import { POLICIES_LIST_CONTAINER_CLASS, POLICY_KINDS } from '../constants';
 import CiliumNetworkPolicy from './cilium_network_policy.vue';
 import ScanExecutionPolicy from './scan_execution_policy.vue';
 
@@ -20,6 +20,11 @@ export default {
     ScanExecutionPolicy,
   },
   props: {
+    containerClass: {
+      type: String,
+      required: false,
+      default: POLICIES_LIST_CONTAINER_CLASS,
+    },
     policy: {
       type: Object,
       required: false,
@@ -41,7 +46,7 @@ export default {
   },
   methods: {
     getDrawerHeaderHeight() {
-      return getContentWrapperHeight('.js-threat-monitoring-container-wrapper');
+      return getContentWrapperHeight(this.containerClass);
     },
   },
   // We set the drawer's z-index to 252 to clear flash messages that might be displayed in the page

ee/app/assets/javascripts/threat_monitoring/components/policy_list.vue

@@ -327,6 +327,7 @@ export default {
 
     <policy-drawer
       :open="hasSelectedPolicy"
+      container-class=".js-threat-monitoring-container-wrapper"
       :policy="selectedPolicy"
       :edit-policy-path="editPolicyPath"
       data-testid="policyDrawer"

ee/app/views/projects/security/policies/show.html.haml

 - breadcrumb_title _("Policies")
+- @content_wrapper_class = 'js-security-policies-container-wrapper'
 - disable_security_policy_project = !can_update_security_orchestration_policy_project?(project)
 - default_environment_id = project.default_environment&.id || -1