feat(trafficrouting): use values array for multiple accepted values under same header name

[schlags]

Fixes #2973

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional with a list of types and scopes found here, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I've signed my commits with DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My builds are green. Try syncing with master if they are not.
• My organization is added to USERS.md.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (fec76d6) 81.74% compared to head (2a26705) 81.75%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2974   +/-   ##
=======================================
  Coverage   81.74%   81.75%           
=======================================
  Files         134      134           
  Lines       20370    20377    +7     
=======================================
+ Hits        16652    16659    +7     
  Misses       2861     2861           
  Partials      857      857           

Files Changed	Coverage Δ
rollout/trafficrouting/alb/alb.go	81.19% <100.00%> (+0.28%)	⬆️

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[github-actions]

Go Published Test Results

2 042 tests   2 042 ✔️  2m 41s ⏱️
   118 suites         0 💤
       1 files           0 ❌

Results for commit 2a26705.

[github-actions]

E2E Tests Published Test Results

    4 files      4 suites   3h 40m 20s ⏱️
102 tests   85 ✔️   6 💤 11 ❌
426 runs  385 ✔️ 24 💤 17 ❌

For more details on these failures, see this check.

Results for commit 2a26705.

♻️ This comment has been updated with latest results.