Adds gameserverallocation e2e tests for Lists

[igooch]

What type of PR is this?

/kind feature

What this PR does / Why we need it:

Adds GameServerAllocation e2e tests for Lists.

Changes GameServerAllocation action to truncate the List to Capacity if only the capacity is changed, to be consistent with the behavior with Counters.

Which issue(s) this PR fixes:

Working on #2716

Special notes for your reviewer:

[agones-bot]

Build Succeeded 👏

Build Id: 4908f353-fdce-4836-8683-69ebb9b51574

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:1.37.0-dev-753508f-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.37.0-dev-753508f-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.37.0-dev-753508f-linux-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.37.0-dev-753508f-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.37.0-dev-753508f-amd64
• Linux C++ SDK (build): agonessdk-1.37.0-dev-753508f-amd64-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.37.0-dev-753508f-amd64.zip

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

• https://753508f-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/googleforgames/agones.git pull/3516/head:pr_3516 && git checkout pr_3516
• helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.37.0-dev-753508f-amd64

[markmandel]

Looks good - just one question, then I think good to merge.

[agones-bot]

Build Succeeded 👏

Build Id: 55c5570a-3d2f-420c-99ef-b72e188fb1ff

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:1.37.0-dev-1767454-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.37.0-dev-1767454-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.37.0-dev-1767454-linux-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.37.0-dev-1767454-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.37.0-dev-1767454-amd64
• Linux C++ SDK (build): agonessdk-1.37.0-dev-1767454-amd64-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.37.0-dev-1767454-amd64.zip

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

• https://1767454-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/googleforgames/agones.git pull/3516/head:pr_3516 && git checkout pr_3516
• helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.37.0-dev-1767454-amd64

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: igooch, markmandel

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [markmandel]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[google-oss-prow]

New changes are detected. LGTM label has been removed.

[agones-bot]

Build Succeeded 👏

Build Id: 6f676fb9-2fd3-4188-95c3-a78266221c73

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:1.37.0-dev-429441c-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.37.0-dev-429441c-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.37.0-dev-429441c-linux-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.37.0-dev-429441c-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.37.0-dev-429441c-amd64
• Linux C++ SDK (build): agonessdk-1.37.0-dev-429441c-amd64-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.37.0-dev-429441c-amd64.zip

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

• https://429441c-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/googleforgames/agones.git pull/3516/head:pr_3516 && git checkout pr_3516
• helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.37.0-dev-429441c-amd64