Removing @Produces("application/json") does not work for Map results

[gastaldi]

@stuartwdouglas apparently this PR does not support this:

    @GET
    public Map<String,String> hello() {
        Map<String,String> t = new HashMap<>();
        t.put("Hey", "Ho");
        return t;
    }

I get the following error while hitting the endpoint:

2020-10-14 00:15:35,726 ERROR [org.jbo.res.res.i18n] (executor-thread-1) RESTEASY002005: Failed executing GET /greeting: org.jboss.resteasy.core.NoMessageBodyWriterFoundFailure: Could not find MessageBodyWriter for response object of type: java.util.HashMap of media type: application/octet-stream
	at org.jboss.resteasy.core.ServerResponseWriter.lambda$writeNomapResponse$3(ServerResponseWriter.java:125)
	at org.jboss.resteasy.core.interception.jaxrs.ContainerResponseContextImpl.filter(ContainerResponseContextImpl.java:404)
	at org.jboss.resteasy.core.ServerResponseWriter.executeFilters(ServerResponseWriter.java:252)
	at org.jboss.resteasy.core.ServerResponseWriter.writeNomapResponse(ServerResponseWriter.java:101)
	at org.jboss.resteasy.core.ServerResponseWriter.writeNomapResponse(ServerResponseWriter.java:74)
	at org.jboss.resteasy.core.SynchronousDispatcher.writeResponse(SynchronousDispatcher.java:594)
	at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:524)
	at org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:261)
	at org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:161)
	at org.jboss.resteasy.core.interception.jaxrs.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:364)
	at org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:164)
	at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:247)
	at io.quarkus.resteasy.runtime.standalone.RequestDispatcher.service(RequestDispatcher.java:73)
	at io.quarkus.resteasy.runtime.standalone.VertxRequestHandler.dispatch(VertxRequestHandler.java:131)
	at io.quarkus.resteasy.runtime.standalone.VertxRequestHandler.access$000(VertxRequestHandler.java:37)
	at io.quarkus.resteasy.runtime.standalone.VertxRequestHandler$1.run(VertxRequestHandler.java:94)
	at io.quarkus.runtime.CleanableExecutor$CleaningRunnable.run(CleanableExecutor.java:231)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
	at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:2046)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1578)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1452)
	at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:29)
	at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:29)
	at java.base/java.lang.Thread.run(Thread.java:834)
	at org.jboss.threads.JBossThread.run(JBossThread.java:479)

Originally posted by @gastaldi in #12566 (comment)

[gastaldi]

Apparently returning a List doesn't work either:

    @GET
    public List<String> hello() {
        return Arrays.asList("hi");
    }

[gastaldi]

Nevermind, I forgot to add quarkus-resteasy-jackson to my sample project