[Uptime] Step screenshot full screen view navigation get stuck at second step

[shahzad31]

In Ping list for browser monitor type we have a thumbnail clicking which leads to full screen view, where user can nav between next/previous steps,

while user goes to second step and tries to come back to 1, even though step number changes, screenshot from second remains visible

[elasticmachine]

Pinging @elastic/uptime (Team:uptime)

[justinkambic]

Tested this out, seems to be working well.

The gif doesn't really show it, but the page image changes as well; the images are just very similar close to the fold.