Java Client Small Clean up Items(#6969)

...lr/src/main/java/com/microsoft/signalr/HubConnection.java

...in/java/com/microsoft/signalr/OkHttpWebSocketWrapper.java

...rc/test/java/com/microsoft/signalr/HubConnectionTest.java

...nalr/src/test/java/com/microsoft/signalr/sample/Chat.java