Kibana version: 6.6.7

Elasticsearch version: 6.6.7

Server OS version: Ubuntu 18.04

Browser version: chrome 72

Browser OS version: Ubuntu 18.04

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

Description of the problem including expected versus actual behavior:
All graphical visualization panels don't have a way to hide the legends

Steps to reproduce:

1. Create a pie chart in kibana
2. Pie chart is shown on screen along with legend
3. Search for an option to remove legend from panel
4. No option to remove legend from panel is available

Errors in browser console (if relevant):

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

Describe the feature: