Bug in creating pie chart, Custom Label

[thekofimensah]

Kibana version: 5.0

Elasticsearch version: 5.0

Server OS version: 5.0

Browser version: Chrome Version 54.0.2840.99

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

Description of the problem including expected versus actual behavior: When starting a pie chart on Kibana, the "Custom Label" field doesn't function as it should. No matter the name I put in the field, the chart shows the default name rather than the one specified in the "Custom label"

Steps to reproduce:

1. Create pie chart
2. Split slices by any aggregation and change "Custom label" to anything
3. Hover over chart to see that the name stays unchanged

[tbragin]

This appears to be a known issue in 4.x: #6605