{containerregistry} Fix Azure#21603: Mention anonymous pull access is a preview feature, available in the Standard and Premium service tiers (Azure#21623)

Fixes Azure#21603

Author: RakeshMohanMSFT

specification/containerregistry/resource-manager/Microsoft.ContainerRegistry/preview/2022-02-01-preview/containerregistry.json

@@ -4435,7 +4435,7 @@
           }
         },
         "anonymousPullEnabled": {
-          "description": "Enables registry-wide pull from unauthenticated clients.",
+          "description": "Enables registry-wide pull from unauthenticated clients. It's in preview and available in the Standard and Premium service tiers.",
           "default": false,
           "type": "boolean"
         }
@@ -4853,7 +4853,7 @@
           }
         },
         "anonymousPullEnabled": {
-          "description": "Enables registry-wide pull from unauthenticated clients.",
+          "description": "Enables registry-wide pull from unauthenticated clients. It's in preview and available in the Standard and Premium service tiers.",
           "type": "boolean"
         }
       }