Add finalizer name change to create gameserver example

[indexjoseph]

What type of PR is this?

/kind cleanup

What this PR does / Why we need it:

Updates the example documentation to reflect finalizer name change

Which issue(s) this PR fixes:

Follow-up of #3840

Special notes for your reviewer:

[agones-bot]

Build Succeeded 🥳

Build Id: 9a0543f1-e317-49a9-9df4-7c40925f5d42

The following development artifacts have been built, and will exist for the next 30 days:

• image: us-docker.pkg.dev/agones-images/ci/agones-controller:1.44.0-dev-70e6d44
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.44.0-dev-70e6d44
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.44.0-dev-70e6d44-linux
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.44.0-dev-70e6d44
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.44.0-dev-70e6d44
• Linux C++ SDK (build): agonessdk-1.44.0-dev-70e6d44-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.44.0-dev-70e6d44.zip

A preview of the website (the last 30 builds are retained):

• https://70e6d44-dot-preview-dot-agones-images.appspot.com/

To install this version:

git fetch https://github.com/googleforgames/agones.git pull/4005/head:pr_4005 && git checkout pr_4005
helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.44.0-dev-70e6d44