added codegen for java OK Http Client (#1300)

* added codegen for  java OK Http Client

* shalika- added snapshot test for -codegen- java -ok http client

* shalika- moving JavaOkHttpClientCodegen in alphabetical order in codegen

helpers/codegen/codegen.js

@@ -15,6 +15,7 @@ import { CsRestSharpCodegen } from "./generators/cs-restsharp"
 import { RubyNetHttpCodeGen } from "./generators/ruby-net-http"
 import { SalesforceApexCodegen } from "./generators/salesforce-apex"
 import { ShellHTTPie } from "./generators/shell-httpie"
+import { JavaOkHttpClientCodegen } from "./generators/java-ok-http-client"
 
 /* Register code generators here.
  * A code generator is defined as an object with the following structure.
@@ -28,6 +29,7 @@ export const codegens = [
   CurlCodegen,
   CsRestSharpCodegen,
   GoNativeCodegen,
+  JavaOkHttpClientCodegen,
   JSAxiosCodegen,
   JSFetchCodegen,
   JSjQueryCodegen,