[FTR][Ownership] Assign aiops, custom branding, etc (elastic#197468)

## Summary

Assign test files to small number of reviewers

### Assignment Reasons

Assigned custom_branding due to
https://github.com/elastic/kibana/blob/main/x-pack/plugins/custom_branding/kibana.jsonc#L4

Assigned response_ops_docs due to the name

Assigned monitoring due to
https://github.com/elastic/kibana/blob/main/x-pack/plugins/monitoring/kibana.jsonc#L4

Assigned so managment due to
https://github.com/elastic/kibana/blob/main/src/plugins/saved_objects_management/kibana.jsonc#L4

Assigned aiops due to
https://github.com/elastic/kibana/blob/main/x-pack/plugins/aiops/kibana.jsonc#L4

Assigned banners_functional due to Pierre being all over the git blame.
:lol:

Assigned x-pack/test/screenshot_creation due to
elastic#197468 (comment)

Contributes to: elastic#194817

.github/CODEOWNERS

@@ -1090,6 +1090,7 @@ src/plugins/discover/public/context_awareness/profile_providers/security @elasti
 # Platform Docs
 /x-pack/test_serverless/functional/test_suites/security/screenshot_creation/index.ts @elastic/platform-docs
 /x-pack/test_serverless/functional/test_suites/security/config.screenshots.ts @elastic/platform-docs
+/x-pack/test/screenshot_creation @elastic/platform-docs
 
 # Visualizations
 /x-pack/test/accessibility/apps/group3/graph.ts @elastic/kibana-visualizations
@@ -1225,6 +1226,7 @@ x-pack/test_serverless/**/test_suites/observability/ai_assistant @elastic/obs-ai
 /x-pack/test_serverless/**/test_suites/observability/infra/ @elastic/obs-ux-infra_services-team
 
 # Elastic Stack Monitoring
+/x-pack/test/functional/services/monitoring @elastic/stack-monitoring
 /x-pack/test/functional/apps/monitoring @elastic/stack-monitoring
 /x-pack/test/api_integration/apis/monitoring @elastic/stack-monitoring
 /x-pack/test/api_integration/apis/monitoring_collection @elastic/stack-monitoring
@@ -1315,12 +1317,17 @@ x-pack/test_serverless/**/test_suites/observability/ai_assistant @elastic/obs-ai
 /x-pack/test/screenshot_creation/services/ml_screenshots.ts @elastic/ml-ui
 /x-pack/test_serverless/**/test_suites/**/ml/ @elastic/ml-ui
 /x-pack/test_serverless/**/test_suites/common/management/transforms/ @elastic/ml-ui
+/x-pack/test/api_integration/services/ml.ts @elastic/ml-ui
 
 # Additional plugins and packages maintained by the ML team.
 /x-pack/test/accessibility/apps/group2/transform.ts  @elastic/ml-ui
 /x-pack/test/api_integration/apis/aiops/ @elastic/ml-ui
 /x-pack/test/api_integration/apis/transform/ @elastic/ml-ui
+/x-pack/test/api_integration_basic/apis/aiops @elastic/ml-ui
 /x-pack/test/api_integration_basic/apis/transform/ @elastic/ml-ui
+/x-pack/test/api_integration/services/aiops.ts @elastic/ml-ui
+/x-pack/test/api_integration/services/transform.ts @elastic/ml-ui
+/x-pack/test/functional/apps/aiops @elastic/ml-ui
 /x-pack/test/functional/apps/transform/ @elastic/ml-ui
 /x-pack/test/functional/services/transform/ @elastic/ml-ui
 /x-pack/test/functional_basic/apps/transform/ @elastic/ml-ui
@@ -1402,6 +1409,7 @@ x-pack/test/api_integration/deployment_agnostic/services/ @elastic/appex-qa
 x-pack/test/**/deployment_agnostic/ @elastic/appex-qa #temporarily to monitor tests migration
 
 # Core
+/x-pack/test/functional/apps/saved_objects_management @elastic/kibana-core
 /x-pack/test/usage_collection @elastic/kibana-core
 /x-pack/test/licensing_plugin @elastic/kibana-core
 /x-pack/test/functional_execution_context @elastic/kibana-core
@@ -1491,6 +1499,7 @@ x-pack/plugins/cloud_integrations/cloud_full_story/server/config.ts @elastic/kib
 #CC# /x-pack/plugins/security/ @elastic/kibana-security
 
 # Response Ops team
+/x-pack/test/screenshot_creation/apps/response_ops_docs @elastic/response-ops
 /x-pack/test/rule_registry @elastic/response-ops @elastic/obs-ux-management-team
 /x-pack/test/accessibility/apps/group3/rules_connectors.ts @elastic/response-ops
 /x-pack/test/functional/es_archives/cases/default @elastic/response-ops
@@ -1988,6 +1997,8 @@ x-pack/test/profiling_api_integration @elastic/obs-ux-infra_services-team
 x-pack/plugins/observability_solution/observability_shared/public/components/profiling @elastic/obs-ux-infra_services-team
 
 # Shared UX
+/x-pack/test/banners_functional @elastic/appex-sharedux
+/x-pack/test/custom_branding @elastic/appex-sharedux
 /x-pack/test/api_integration/apis/content_management @elastic/appex-sharedux
 /x-pack/test/accessibility/apps/group3/tags.ts @elastic/appex-sharedux
 /x-pack/test/accessibility/apps/group3/snapshot_and_restore.ts @elastic/appex-sharedux