Added missing env to flag mapping

[valentintorikian]

What type of PR is this?

Uncomment only one /kind <> line, press enter to put that in a new line, and remove leading whitespace from that line:

/kind breaking

/kind bug

/kind cleanup
/kind documentation
/kind feature
/kind hotfix

What this PR does / Why we need it:

On the allocator the following env to config mapping were missing:

REMOTE_ALLOCATION_TIMEOUT
TOTAL_REMOTE_ALLOCATION_TIMEOUT
ALLOCATION_BATCH_WAIT_TIME

On the controller the following mapping was missing:

ALLOCATION_BATCH_WAIT_TIME

The effect is that the value of those flag was completely ignored when parsing the environment and falling back to the default value.

Which issue(s) this PR fixes:

N/A
Special notes for your reviewer:

[valentintorikian]

/assign @roberthbailey

[agones-bot]

Build Succeeded 👏

Build Id: 6699a067-13c0-4ea4-a071-b8472bf677aa

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:1.26.0-5c4eb62-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.26.0-5c4eb62-linux-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.26.0-5c4eb62-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.26.0-5c4eb62-amd64
• Linux C++ SDK (build): agonessdk-1.26.0-5c4eb62-amd64-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.26.0-5c4eb62-amd64.zip

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

• https://5c4eb62-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/googleforgames/agones.git pull/2728/head:pr_2728 && git checkout pr_2728
• helm install agones ./install/helm/agones --namespace agones-system --set agones.image.tag=1.26.0-5c4eb62-amd64

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: roberthbailey, valentintorikian

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• OWNERS [roberthbailey]

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[agones-bot]

Build Succeeded 👏

Build Id: b1a84c92-b5a1-4b0c-9a2b-5e03a00fdfc7

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:1.26.0-682beb5-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.26.0-682beb5-linux-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.26.0-682beb5-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.26.0-682beb5-amd64
• Linux C++ SDK (build): agonessdk-1.26.0-682beb5-amd64-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.26.0-682beb5-amd64.zip

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

• https://682beb5-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/googleforgames/agones.git pull/2728/head:pr_2728 && git checkout pr_2728
• helm install agones ./install/helm/agones --namespace agones-system --set agones.image.tag=1.26.0-682beb5-amd64