Add platform flag for docker build without a reliance on docker buildx

[pguinard-public-com]

Before this PR

Platform flag is only supported for docker buildx and not docker.

Example of the docker command we would like to run:

docker build --platform linux/arm64 -t example .

After this PR

The platform flag will be supported such as this to build for a single platform:

docker {
    name "example:$version"
    platform "arm64"

Possible downsides?

On upgrade from one version to a version with this commit in it while having the platform flag in a non working state would cause gradle to throw errors rather than silently ignore.

[palantirtech]

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[changelog-app[bot]]

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Type See change types. Select one:

• [ ] Feature
• [ ] Improvement
• [ ] Fix
• [ ] Break
• [ ] Deprecation
• [ ] Manual task
• [ ] Migration

Description Add platform flag for docker build without a reliance on docker buildx

Before this PR

Platform flag is only supported for docker buildx and not docker.

Example of the docker command we would like to run:

docker build --platform linux/arm64 -t example .

After this PR

The platform flag will be supported such as this to build for a single platform:

docker {
    name "example:$version"
    platform "arm64"

Possible downsides?

On upgrade from one version to a version with this commit in it while having the platform flag in a non working state would cause gradle to throw errors rather than silently ignore.

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