[JIRAALIGN-2086] User icon is not descriptive on iteration board in team room

Issue Summary

User icon is not descriptive on iteration board in team room. If a user does not have an icon, it shows the user's initials everywhere except for on the cards on the board. See screenshot

Steps to Reproduce

1. Pick a team user with no profile pic
2. Navigate to iteration board on team room
3. Notice upper-right user icon and the same user's icon on the cards

Expected Results

User icon should show user's initials on both the scrum team's sprint board AND on the kanban board in team room. 

Actual Results

User icon is blank

Workaround

no workaround