Fix Insights DORA `deployment_frequency` to return `frequency` not `total`.

What is the current bug behavior?

Currently Insights deployment_frequency query.metric return total deployments and not daily average per the selected time period.

Related to Inconsistency in DORA API Deployment_Frequency ... (#371271 - closed)

What is the expected correct behavior?

deployment_frequency should return frequency not total.

Update Insights DORA query.metric, to return daily average per the selected time period and not total deployments.