[JIRAALIGN-1530] Average Team Velocity Counts Are Showing Incorrectly Between The Three Key Areas (Capacity Planning, Team Room, & Backlog) Locations

Issue Summary

We have found that there is some inconsistency between the average velocity between the 3 locations Team Room, Capacity Planning, & Backlog. Please see the screenshots attached showing the discrepancy. Keep in mind the team velocity wasn't overridden at all. 

Steps to Reproduce

1. Step- Compare average team velocity for a team iteration for the following areas. 
   1. Capacity Planning
   2. Team Room
   3. Backlog

Expected Results

1. Capacity Planning, Team Room, and Backlog should display "Average Velocity" as the average sum of accepted stories from the last 5 completed sprints (including the selected sprint in the dropdown if it's one of the team's last 5 completed sprints)

2. The "Avg Velocity" field on the sprint panel should only display a read-only value of the "Average Velocity" value from #1

3. "Override velocity" field should be added to sprint panel right below "Avg Velocity". This value should be linked to "Override" value on backlog (list and kanban views). So if a user enters a number value on the "Override velocity" field on panel, it will render on the backlog "Override" and vice versa

Actual Results

We are seeing different average velocity totals

Workaround

N/A