[APM] Clicking on all the graph keys makes the graph disappear

[liza-mae]

Kibana version: 6.2.2 BC1

Elasticsearch version: 6.2.2 BC1

Server OS version: Ubuntu tar

Browser version: Chrome latest

Browser OS version: OSX

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

Description of the problem including expected versus actual behavior:

Graph disappears when you click on all the graph keys

Steps to reproduce:

Install Elasticsearch, Kibana and APM
Import APM data
Go to APM
Click on all the graph keys, the graph disappears

[liza-mae]

@beniwohli said to close this issue, as the PR is already being worked on for 6.3

https://github.com/elastic/x-pack-kibana/pull/4390