message: add x-ms-client-default to schema
diff: "x-ms-parameter-location": {
  "$ref": "#/definitions/xmsParameterLocation"
  },
  + "x-ms-client-default": {
  + "$ref": "#/definitions/xmsClientDefault"
  + },
  "x-ms-header-collection-prefix": {
  "type": "string",
  "description": "Provides the ability to specify a key value mapping, using given prefix as the prefix of all keys."
  "x-ms-parameter-location": {
  "$ref": "#/definitions/xmsParameterLocation"
  },
  + "x-ms-client-default": {
  + "$ref": "#/definitions/xmsClientDefault"
  + },
  "x-ms-client-name": {
  "type": "string",
  "description": "A code-generator-friendly name for the parameter."
  "x-ms-parameter-location": {
  "$ref": "#/definitions/xmsParameterLocation"
  },
  + "x-ms-client-default": {
  + "$ref": "#/definitions/xmsClientDefault"
  + },
  "x-ms-client-name": {
  "type": "string",
  "description": "A code-generator-friendly name for the parameter."
  "x-ms-parameter-location": {
  "$ref": "#/definitions/xmsParameterLocation"
  },
  + "x-ms-client-default": {
  + "$ref": "#/definitions/xmsClientDefault"
  + },
  "x-ms-client-name": {
  "type": "string",
  "description": "A code-generator-friendly name for the parameter."
  "x-ms-parameter-location": {
  "$ref": "#/definitions/xmsParameterLocation"
  },
  + "x-ms-client-default": {
  + "$ref": "#/definitions/xmsClientDefault"
  + },
  "x-ms-client-name": {
  "type": "string",
  "description": "A code-generator-friendly name for the parameter."
  "x-ms-client-flatten": {
  "$ref": "#/definitions/xmsClientFlatten"
  },
  + "x-ms-client-default": {
  + "$ref": "#/definitions/xmsClientDefault"
  + },
  "x-ms-client-name": {
  "type": "string"
  },
  "method"
  ]
  },
  + "xmsClientDefault": {
  + "type": [
  + "string",
  + "boolean",
  + "number"
  + ]
  + },
  "xmsMutability": {
  "type": "array",
  "items": {
  