Backport of NET-9178-Consul-api-gateway-not-starting-after-restart into release/1.2.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #3978 to be assessed for backporting due to the inclusion of the label backport/1.2.x.

The below text is copied from the body of the original PR.

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Changes proposed in this PR

• If role already exists, don't error out of connect inject.

How I've tested this PR

• Local build, create api gateway, delete connect inject. Before this change, connect inject would crash with 'role already exists', after this change, connect inject ignores that the role already exists and continues to operate as expected.

How I expect reviewers to test this PR

• Local Build, CI passes

Checklist

• Tests added
• CHANGELOG entry added

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Overview of commits

• a0ca997 - 582fddc - 3c1cab1