Fix the status handler

Turns out to be a nasty problem with instantiating some kinds
of handlers (those that don't take a parameter)

Interesting story: the lambda was created automatically by
a refactoring IDE. Each individual step was correct, except
the last one, which took a method call (`constructor.newInstance()`)
and turned into a method referened (`constructor::newInstance`).

When called, the original version of this didn't pass any
arguments, and everything was fine. The mathod reference version,
however, caused the sessionId to be passed to the `newInstance`
method as argument, causing grief. Still. Fixed now.

Author: shs96c

java/server/src/org/openqa/selenium/remote/server/rest/ResultConfig.java

@@ -204,29 +204,19 @@ public Throwable getRootExceptionCause(Throwable originalException) {
   private HandlerFactory getHandlerFactory(Class<? extends RestishHandler<?>> handlerClazz) {
     final Constructor<? extends RestishHandler<?>> sessionAware = getConstructor(handlerClazz, Session.class);
     if (sessionAware != null) {
-      return new HandlerFactory() {
-        @Override
-        public RestishHandler<?> createHandler(SessionId sessionId) throws Exception {
-          return sessionAware.newInstance(sessionId != null ? sessions.get(sessionId) : null);
-        }
-      };
+      return (sessionId) ->
+          sessionAware.newInstance(sessionId != null ? sessions.get(sessionId) : null);
     }
 
     final Constructor<? extends RestishHandler> driverSessions =
         getConstructor(handlerClazz, DriverSessions.class);
     if (driverSessions != null) {
-      return new HandlerFactory() {
-        @Override
-        public RestishHandler<?> createHandler(SessionId sessionId) throws Exception {
-          return driverSessions.newInstance(sessions);
-        }
-      };
+      return (sessionId) -> driverSessions.newInstance(sessions);
     }
 
-
-    final Constructor<? extends RestishHandler> norags = getConstructor(handlerClazz);
-    if (norags != null) {
-      return norags::newInstance;
+    final Constructor<? extends RestishHandler> noArgs = getConstructor(handlerClazz);
+    if (noArgs != null) {
+      return (sessionId) -> noArgs.newInstance();
     }
 
     throw new IllegalArgumentException("Don't know how to construct " + handlerClazz);