[Uptime] Detect if user has out of sync clock in kibana/heartbeat

[shahzad31]

We often times gets users SDH's around where they can't see monitors in overview list and snapshot count, but they can see the data in pings over time chart.

This happens when the system where heartbeat is running or system where kibana is running, it's clock goes out of sync, for example it get's set to 5-6 mins in future.

In that case, the timespan filter we have in snapshot query and overview list, will filter out the data, the way it works is that it only checks for some relative date ranges like last 15mins, in that case, it will check if user has any last run with in now-5m with the monitor timespan overlap filter. So if clock goes out of sync, now-5m timespan filter get's broken and it ends up filtering monitors.

https://github.com/elastic/kibana/blob/27ab5346314e3a32c92c51b0fc2b72aba57fd531/x-pack/plugins/uptime/server/lib/requests/search/query_context.ts#L106

We should detect this scenario in the monitor list and guide user to check their clock to make sure everything works as expected

[justinkambic]

Post-FF Testing LGTM