feat(translator): support setting previous priorities retry predicate

[Inode1]

What type of PR is this?

What this PR does / why we need it:

Makes it possible to configure the previous priorities retry for Route.

Which issue(s) this PR fixes:

Fixes #6181

Release Notes: Yes/No

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 70.48%. Comparing base (32d61c4) to head (0a51999).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/xds/translator/route.go	76.92%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6204   +/-   ##
=======================================
  Coverage   70.48%   70.48%           
=======================================
  Files         220      220           
  Lines       36676    36691   +15     
=======================================
+ Hits        25852    25863   +11     
- Misses       9292     9294    +2     
- Partials     1532     1534    +2     

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[Inode1]

/retest

[arkodg]

Suggested change

	// If not specified or set to 0, all requests are sent to the highest priority.
	// If not specified or set to 0, all requests are sent to the highest priority that is healthy.

[arkodg]

thanks @Inode1 the PR looks good, added a minor comment
can you also add a test in https://github.com/envoyproxy/gateway/tree/main/internal/gatewayapi/testdata ?

[Inode1]

thanks @Inode1 the PR looks good, added a minor comment can you also add a test in https://github.com/envoyproxy/gateway/tree/main/internal/gatewayapi/testdata ?

Done

[Inode1]

/retest

[arkodg]

LGTM thanks