Kibana: Unexpected behavior when enabling stack monitoring on ESS

[simitt]

Kibana version: 7.8 (unreleased)

Steps to reproduce:

1. Create 7.8 deployment on ESS and try to enable stack monitoring. It asks whether or not to enable metricbeat or internal monitoring. There is no possibility to set up monitoring with metricbeat on ESS though.

1. Clicking on Setup with metricbeat takes me to the Elasticsearch node
   

2. Trying to see how to set up monitoring for APM takes me to a blank monitoring screen (no data)
   

   1. Finally setting up internal monitoring leads to a deprecation warning and the suggestion to switch to metricbeat based monitoring. The internal monitoring worked as expected, but the migration message seems confusing.
      

pinging @chrisronline
fyi @graphaelli

[elasticmachine]

Pinging @elastic/stack-monitoring (Team:Monitoring)

[chrisronline]

@simitt I have verified this is happening.

My guess is https://github.com/elastic/kibana/pull/62908 introduced a bug where we aren't properly detected cloud.

It looks like we need to specify the cloud plugin in our kibana.json file, like other plugins do

cc @igoristic