Ensure disable_iss_validation is properly set.

[benashz]

In vault-1.9 disable_iss_validation defaulted to true, which exposed an
issue in the kubernetes_auth_backend_config resource. The resource never
honoured the configuration of the related field when it was set to false.

Community Note

• Please vote on this pull request by adding a 👍 reaction to the original pull request comment to help the community and maintainers prioritize this request
• Please do not leave "+1" comments, they generate extra noise for pull request followers and do not help prioritize the request

Release note for CHANGELOG:

Output from acceptance testing:

$ make dev testacc TESTARGS='-v -test.run  TestAccKube'                      
==> Checking that code complies with gofmt requirements...
go build -o terraform-provider-vault
mv terraform-provider-vault ~/.terraform.d/plugins/
TF_ACC=1 go test $(go list ./...) -v -v -test.run  TestAccKube -timeout 20m

[...]

PASS
ok      github.com/hashicorp/terraform-provider-vault/util      0.342s [no tests to run]
=== RUN   TestAccKubernetesAuthBackendConfigDataSource_basic
--- PASS: TestAccKubernetesAuthBackendConfigDataSource_basic (3.28s)
=== RUN   TestAccKubernetesAuthBackendConfigDataSource_full
--- PASS: TestAccKubernetesAuthBackendConfigDataSource_full (3.00s)
=== RUN   TestAccKubernetesAuthBackendRoleDataSource_basic
--- PASS: TestAccKubernetesAuthBackendRoleDataSource_basic (2.98s)
=== RUN   TestAccKubernetesAuthBackendRoleDataSource_full
--- PASS: TestAccKubernetesAuthBackendRoleDataSource_full (3.01s)
=== RUN   TestAccKubernetesAuthBackendConfig_import
--- PASS: TestAccKubernetesAuthBackendConfig_import (3.89s)
=== RUN   TestAccKubernetesAuthBackendConfig_basic
--- PASS: TestAccKubernetesAuthBackendConfig_basic (1.75s)
=== RUN   TestAccKubernetesAuthBackendConfig_update
--- PASS: TestAccKubernetesAuthBackendConfig_update (3.03s)
=== RUN   TestAccKubernetesAuthBackendConfig_full
--- PASS: TestAccKubernetesAuthBackendConfig_full (1.77s)
=== RUN   TestAccKubernetesAuthBackendConfig_fullUpdate
--- PASS: TestAccKubernetesAuthBackendConfig_fullUpdate (3.05s)
=== RUN   TestAccKubernetesAuthBackendRole_import
--- PASS: TestAccKubernetesAuthBackendRole_import (2.19s)
=== RUN   TestAccKubernetesAuthBackendRole_basic
--- PASS: TestAccKubernetesAuthBackendRole_basic (1.74s)
=== RUN   TestAccKubernetesAuthBackendRole_update
--- PASS: TestAccKubernetesAuthBackendRole_update (3.04s)
=== RUN   TestAccKubernetesAuthBackendRole_full
--- PASS: TestAccKubernetesAuthBackendRole_full (1.76s)
=== RUN   TestAccKubernetesAuthBackendRole_fullUpdate
--- PASS: TestAccKubernetesAuthBackendRole_fullUpdate (6.80s)
PASS
ok      github.com/hashicorp/terraform-provider-vault/vault     43.417s

...