Add RetryHelper to AIA test

[vcsjones]

Fixes #104375

This test failed with:

 Assert.NotEqual() Failure: Values are equal
      Expected: Not False
      Actual:       False

Since it expected "not false" (true) that means the theory that failed was AiaResponseKind.Cert.

"Working" AIA can be flaky and depends on the whims of the OS chain builder and pressure on CI for timeouts. All other AIA tests use RetryHelper, but this one did not. So let's add it to this one, too.