Part of #18714: Replacing deprecated constants in Avatar-Base folder

[rohiiittttt]

Explanation

1. This PR is a part of Replace deprecated constants with enums #18714

Replaced deprecated design system and storybook constants in the avatar-base
ui/components/component-library/avatar-base

Screenshots/Screencaps

Before

After

yarn jest

Manual Testing Steps

Pre-merge author checklist

• I've clearly explained:
  • What problem this PR is solving
  • How this problem was solved
  • How reviewers can test my changes
• Sufficient automated test coverage has been added

Pre-merge reviewer checklist

• Manual testing (e.g. pull and build branch, run in browser, test code being changed)
• PR is linked to the appropriate GitHub issue
• IF this PR fixes a bug in the release milestone, add this PR to the release milestone

If further QA is required (e.g. new feature, complex testing steps, large refactor), add the Extension QA Board label.

In this case, a QA Engineer approval will be be required.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[georgewrmarshall]

LGTM! Thanks for your contribution @rohiiittttt

[NidhiKJha]

LGTM! Need the build to pass. Then we can merge this Pr

[codecov]

Codecov Report

Merging #19408 (50969dc) into develop (16e07b5) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop   #19408      +/-   ##
===========================================
- Coverage    69.94%   69.93%   -0.01%     
===========================================
  Files          959      959              
  Lines        36822    36822              
  Branches      9455     9455              
===========================================
- Hits         25753    25751       -2     
- Misses       11069    11071       +2     

Impacted Files	Coverage Δ
...ents/component-library/avatar-base/avatar-base.tsx	100.00% <ø> (ø)

... and 2 files with indirect coverage changes