Incorrect dialog when upgrading from Basic to Gold

[LeeDr]

Kibana version: 6.4.0 BC2

Elasticsearch version: 6.4.0 BC2

Server OS version: Ubuntu 16

Browser version: Chrome

Browser OS version: Ubuntu 16

Original install method (e.g. download page, yum, from source, etc.): .deb files

Describe the bug:
When uploading a Gold license from my current Basic default license I get this confirm dialog which says I will lose field and document level access control. But those are Platinum features.
I don't think I lose anything when going from Basic to Gold. In fact I gain features like security (not not field and document level).

Steps to reproduce:

1. Start the default distribution with Basic license
2. Install Gold license
3. Check prompt

Expected behavior:
I'm thinking it probably doesn't need a confirm dialog when I'm upgrading license levels?

Screenshots (if relevant):

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

Any additional context:

[LeeDr]

Just a note, that the dialog above isn't the correct info for Platinum to Gold transition either. This is that transition's dialog and it looks correct;

[LeeDr]

Caused by elastic/elasticsearch#29825
Although I see this isn't a Kibana bug, I'd like to leave this open so that the next time someone sees this issue and searches Kibana repo for an open issue on it they'll find this.

[elasticmachine]

Pinging @elastic/kibana-platform

[yuliacech]

This issue is still reproducible in License Management and the messages are directly displayed from an ES AIP request.
We should update this code to not show 'lost' features when upgrading a license to a better tier. When downgrading the license to a worse tier, the message should be configured in frontend so that is can be translated.