add "x-ms-secret": true to secret field (#16436)

* add "x-ms-secret": true to secret field

* remove breaking change prop

* Update example

Co-authored-by: Nan Jiang <naji@microsoft.com>

Author: najian

specification/servicelinker/resource-manager/Microsoft.ServiceLinker/preview/2021-11-01-preview/examples/PatchLink.json

@@ -25,8 +25,7 @@
           "authInfo": {
             "authType": "servicePrincipalSecret",
             "clientId": "name",
-            "principalId": "id",
-            "secret": "secret"
+            "principalId": "id"
           },
           "targetId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/test-rg/providers/Microsoft.DocumentDb/databaseAccounts/test-acc/mongodbDatabases/test-db"
         }
@@ -41,8 +40,7 @@
           "authInfo": {
             "authType": "servicePrincipalSecret",
             "clientId": "name",
-            "principalId": "id",
-            "secret": "secret"
+            "principalId": "id"
           },
           "targetId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/test-rg/providers/Microsoft.DocumentDb/databaseAccounts/test-acc/mongodbDatabases/test-db"
         }

specification/servicelinker/resource-manager/Microsoft.ServiceLinker/preview/2021-11-01-preview/servicelinker.json

@@ -485,7 +485,8 @@
         },
         "secret": {
           "description": "Secret for servicePrincipal auth.",
-          "type": "string"
+          "type": "string",
+          "x-ms-secret": true
         }
       },
       "required": [
@@ -514,7 +515,8 @@
         },
         "certificate": {
           "description": "ServicePrincipal certificate for servicePrincipal auth.",
-          "type": "string"
+          "type": "string",
+          "x-ms-secret": true
         }
       },
       "required": [