Adjust help center unread icon

[heavyweight]

Before	After
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Related to #
#97930

Proposed Changes

• Adjust help center unread icon to match unread notification size

Why are these changes being made?

• The help center unread icon should match better the unread notification circle
• This PR adjusts the size, position and stroke color of the circle of the help center icon

Testing Instructions

• Test in wp-calypso and wp-admin how the unread indicator of the help center icon looks

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
  • For UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-909fdcb90b0776efb7cabdbdf4707e9e1dc79de4

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-909fdcb90b0776efb7cabdbdf4707e9e1dc79de4&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-909fdcb90b0776efb7cabdbdf4707e9e1dc79de4&env=a8c-for-agencies

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[escapemanuele]

Nice!