[Metrics UI] Inventory Threshold rule does not honor "time unit"

[simianhacker]

Kibana version:
main

Elasticsearch version:
main

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

Describe the bug:
When the user sets the "FOR LAST x units" the query for the Inventory Alerts defaults to 60s. This is due to the fact that we are not setting forceInterval on the timerange for getNodes.

Steps to reproduce:

1. Index some Metricbeat data
2. Create an inventory threshold alert that will trigger on 30 minutes of data
3. Alert will fire on 60s

Expected behavior:
Honor the time unit.

[elasticmachine]

Pinging @elastic/infra-monitoring-ui (Team:Infra Monitoring UI)

[nugroho-exp]

@simianhacker Will the fix be backported to 7.x? We have this issue in our 7.16.2 server.

Will the fix also resolve the stack alert issue below as it is quite annoying to get an alert for 1 minute CPU spike? #116128

Thank you.