[Uptime] Overlaid nav buttons inside synthetics screenshot are not canceling default event

[justinkambic]

Kibana version:

8.x

Elasticsearch version:

8.x

Server OS version:

macOS

Browser version:

Chrome 91

Browser OS version:

macOS

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

from source

Describe the bug:

There are overlaid buttons on the thumbnails displayed of synthetics journey step screenshots. They're supposed to prevent default even propagation (the default click handler will drill into the journey), but they seem to not be doing that.

Steps to reproduce:

1. Open Synthetics
2. Hover over a step screenshot
3. Click the overlay (it should move to the next step screenshot)
4. The browser will navigate to the journey summary page

Expected behavior:

The browser should cycle to the next step screenshot

Screenshots (if relevant):

Jun-08-2021.12-36-08.mp4

Errors in browser console (if relevant):

N/A

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

N/A

Any additional context:

N/A

[elasticmachine]

Pinging @elastic/uptime (Team:uptime)