Fix metrics instruments not updating in mobile view

[JamesNK]

Description

Fix regression from #7549 (oops) where the tree doesn't update in mobile view.

Also, I noticed the indent in the mobile view for the metrics page didn't match the new indent of the header.

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No
• Does the change require an update in our Aspire docs?
  • Yes
    • Is this introducing a breaking change?
      • Yes
        • Link to aspire-docs issue (please use this breaking-change template):
      • No
        • Link to aspire-docs issue (please use this doc-idea template):
  • No

[JamesNK]

/backport to release/9.1

[Copilot]

Copilot reviewed 2 out of 3 changed files in this pull request and generated no comments.

Files not reviewed (1)

• src/Aspire.Dashboard/Components/Pages/Metrics.razor.css: Language not supported

[github-actions]

Started backporting to release/9.1: https://github.com/dotnet/aspire/actions/runs/13322202360

[eerhardt]

LGTM

[danmoseley]

@adamint could you please review this and the port PR today