truncate policy status if more than 16 ancestors

[guydc]

What type of PR is this?

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #5228

Release Notes: Yes/No

[codecov]

Codecov Report

Attention: Patch coverage is 38.31776% with 66 lines in your changes missing coverage. Please review.

Project coverage is 66.83%. Comparing base (a58021e) to head (9d5f455).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/gatewayapi/status/policy.go	0.00%	24 Missing ⚠️
internal/gatewayapi/clienttrafficpolicy.go	12.50%	13 Missing and 1 partial ⚠️
internal/gatewayapi/envoyextensionpolicy.go	12.50%	13 Missing and 1 partial ⚠️
internal/gatewayapi/securitypolicy.go	12.50%	13 Missing and 1 partial ⚠️

❌ Your patch check has failed because the patch coverage (38.31%) is below the target coverage (60.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5261      +/-   ##
==========================================
- Coverage   66.89%   66.83%   -0.07%     
==========================================
  Files         210      210              
  Lines       33027    33142     +115     
==========================================
+ Hits        22093    22150      +57     
- Misses       9593     9651      +58     
  Partials     1341     1341              

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