Kibana version: 7.9.0

Elasticsearch version: 7.9.0

Server OS version: Ubuntu

Browser version: MS Edge 84.0.522.63

Browser OS version: macOS 10.14.6

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

Describe the bug:
Cannot edit index pattern fields if they contain certain characters. Examples:

• Memory: Allocated Bytes/sec
• Memory: # Bytes in all Heaps

Steps to reproduce:

1. Go to Stack Management.
2. Go to Index patterns.
3. Select an index pattern.
4. Click on the pen icon to edit the field.

Expected behavior:
Should be able to edit the field.

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

• index pattern doesn't have a scripted field called 'Memory: Allocated Bytes'
• index pattern doesn't have a scripted field called 'Memory: '

Screenshots