Update keyvault.json

Author: jlichwa

specification/keyvault/resource-manager/Microsoft.KeyVault/stable/2018-02-14/keyvault.json

@@ -1176,7 +1176,7 @@
           "items": {
             "$ref": "#/definitions/AccessPolicyEntry"
           },
-          "description": "An array of 0 to 16 identities that have access to the key vault. All identities in the array must use the same tenant ID as the key vault's tenant ID."
+          "description": "An array of 0 to 1024 identities that have access to the key vault. All identities in the array must use the same tenant ID as the key vault's tenant ID."
         },
         "enabledForDeployment": {
           "type": "boolean",