Updates Kubernetes templates for cpp-simple image

[0xaravindh]

What type of PR is this?

/kind cleanup

What this PR does / Why we need it:

• Updated the instructions for bumping the cpp-simple image version and pushing it to the cloud build.

Which issue(s) this PR fixes:

Works #4040

Special notes for your reviewer:

[agones-bot]

Build Succeeded 🥳

Build Id: a34d324b-f1cb-408e-808c-fd6829d3d886

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:1.46.0-dev-5b4de8f
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.46.0-dev-5b4de8f
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.46.0-dev-5b4de8f-linux
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.46.0-dev-5b4de8f
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.46.0-dev-5b4de8f
• Linux C++ SDK (build): agonessdk-1.46.0-dev-5b4de8f-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.46.0-dev-5b4de8f.zip

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

• https://5b4de8f-dot-preview-dot-agones-images.appspot.com/

To install this version:

git fetch https://github.com/googleforgames/agones.git pull/4044/head:pr_4044 && git checkout pr_4044
helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.46.0-dev-5b4de8f