Update host "Used by" column heading

[rachaelshaw]

Related issue: Resolves #40189

Checklist for submitter

If some of the following don't apply, delete the relevant line.

• Changes file added for user-visible changes in changes/, orbit/changes/ or ee/fleetd-chrome/changes.
  See Changes files for more information.

Testing

• QA'd all new/changed functionality manually

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 66.31%. Comparing base (d6fd6e2) to head (a7022f3).
⚠️ Report is 10 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #40190      +/-   ##
==========================================
- Coverage   66.31%   66.31%   -0.01%     
==========================================
  Files        2453     2453              
  Lines      196617   196616       -1     
  Branches     8696     8590     -106     
==========================================
- Hits       130385   130384       -1     
  Misses      54420    54420              
  Partials    11812    11812              

Flag	Coverage Δ
frontend	54.18% <ø> (-0.01%)	⬇️

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