Individual index management page is not announced in screenreader when launched

[bhavyarm]

Kibana version: 6.3.0 BC6

Browser version: chrome latest

Browser OS version: OS X

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

Describe the bug: When you click on an index on index management page - the page which opens up to manage that particular index is not announced in screenreader.

Steps to reproduce:

1. Use voiceover
2. Go to index management and click on an individual
3. The euiFlyout which opens up is not announced in the screenreader - only tabs within it are announced.

Expected behavior: Screenreader should announce the launch of flyout(am using eui term which I see in the console. Might be wrong)

Screenshots (if relevant):