message: Add servicePrincipalsByAppId method to Graph Api
  Example : GET /72f988bf-86f1-41af-91ab-2d7cd011db47/servicePrincipalsByAppId/9469b9f5-6722-4481-a2b2-14ed560b706f/objectId?api-version=1.6 HTTP/1.1
  {"odata.metadata":"https://graph.windows.net/72f988bf-86f1-41af-91ab-2d7cd011db47/$metadata#Edm.String","value":"3eb9d9f3-371c-4d24-a60a-d7681c48c071"}
diff: "x-ms-odata": "#/definitions/ServicePrincipal"
  }
  },
  + "/{tenantID}/servicePrincipalsByAppId/{applicationID}/objectId": {
  + "get": {
  + "tags": [
  + "ServicePrincipalsByAppId"
  + ],
  + "operationId": "ServicePrincipalsByAppId_Get",
  + "description": "Gets an object id for a given application id from the current tenant.",
  + "parameters": [
  + {
  + "$ref": "#/parameters/ApiVersionParameter"
  + },
  + {
  + "$ref": "#/parameters/tenantIDInPath"
  + },
  + {
  + "$ref": "#/parameters/applicationIdInPath"
  + }
  + ],
  + "responses": {
  + "200": {
  + "description": "OK. The operation was successful.",
  + "schema": {
  + "$ref": "#/definitions/ServicePrincipalObjectResult"
  + }
  + },
  + "default": {
  + "description": "Error response describing why the operation failed.",
  + "schema": {
  + "$ref": "#/definitions/GraphError"
  + }
  + }
  + }
  + }
  + },
  "/{tenantID}/servicePrincipals/{objectId}": {
  "patch": {
  "tags": [
  },
  "description": "Application list operation result."
  },
  + "ServicePrincipalObjectResult": {
  + "type": "object",
  + "properties": {
  + "value": {
  + "type": "string",
  + "description": "Service Principal Application Object Id"
  + },
  + "odata.metadata": {
  + "type": "string",
  + "description": "The URL representing edm equivalent."
  + }
  + },
  + "description": "Service Principal Object Result."
  + },
  "AppRole": {
  "type": "object",
  "properties": {
  "type": "string",
  "description": "The tenant ID.",
  "x-ms-parameter-location": "client"
  + },
  + "applicationIdInPath": {
  + "name": "applicationID",
  + "in": "path",
  + "required": true,
  + "type": "string",
  + "description": "The application ID.",
  + "x-ms-parameter-location": "client"
  }
  }
  }
  