Fix IAMAuthPolicy reconciliation loop on invalid service name override

[SinghVikram97]

What type of PR is this?
Fix

Which issue does this PR fix:
Fix IAMAuthPolicy reconciliation loop on invalid service name override

Testing done on this change:

Tests for IAMAuthPolicy pass including the skipped one

Ran 9 of 135 Specs in 151.463 seconds
SUCCESS! -- 9 Passed | 0 Failed | 0 Pending | 126 Skipped
--- PASS: TestIntegration (151.47s)
PASS
ok      github.com/aws/aws-application-networking-k8s/test/suites/integration   151.501s

(25-12-04 20:03:27) <0> [~/eks-fork/aws-application-networking-k8s-fork]  

Do all end-to-end tests successfully pass when running make e2e-test?:

Yes

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.