Merge pull request #5506 from nawazkh/nhk_add_1.19_metadata

add release 1.19 to CAPZ metadata

Author: k8s-ci-robot

metadata.yaml

@@ -71,3 +71,6 @@ releaseSeries:
   - major: 1
     minor: 18
     contract: v1beta1
+  - major: 1
+    minor: 19
+    contract: v1beta1