make container app/entrypoint argument defaults only happen on the RID-specific builds, not the outer RID-less build

[baronfel]

Fixes dotnet/sdk-container-builds#623

Pulls the entrypoint/appcommand calculations out of the outer-level and puts them on a Target that is computed for each RID. This allows for RID-specific commands (useful for Windows containers vs Linux) and prevents the duplication reported in the linked issue.

PR Overview

This PR refactors the container entrypoint/appcommand logic to compute its parameters on a RID-specific target, allowing for different behavior on Windows versus Linux containers and preventing duplicate configurations.

• Moves the entrypoint/appcommand property out of the outer-level and onto a per-RID target
• Updates tests to reference the newly introduced RID-specific property

Reviewed Changes

File	Description
src/Containers/Microsoft.NET.Build.Containers/KnownStrings.cs	Added a new static property for container execution arguments
test/Microsoft.NET.Build.Containers.IntegrationTests/TargetsTests.cs	Updated test build invocations to use the new property for RID-specific behavior

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

src/Containers/Microsoft.NET.Build.Containers/KnownStrings.cs:30

• The property name '_ComputeContainerExecutionArgs' starts with an underscore, which is inconsistent with the PascalCase naming used for other public static properties. Consider renaming it to 'ComputeContainerExecutionArgs' to maintain consistency.

public static readonly string _ComputeContainerExecutionArgs = nameof(_ComputeContainerExecutionArgs);

[MattKotsenas]

I see tests were updated, but flagging if more tests should be written to cover this scenario?

[baronfel]

There are other tests that actually run the publish and assert that args were passed/built, but those tests use the public surface area (PublishContainer) and so are modeling the end-user experience already.

[baronfel]

/backport to release/9.0.3xx

[github-actions]

Started backporting to release/9.0.3xx: https://github.com/dotnet/sdk/actions/runs/13793114191

[github-actions]

@baronfel backporting to "release/9.0.3xx" failed, the patch most likely resulted in conflicts:

$ git am --3way --empty=keep --ignore-whitespace --keep-non-patch changes.patch

Applying: make container app/entrypoint argument defaults only happen on the RID-specific builds, not the outer RID-less build
Using index info to reconstruct a base tree...
M	src/Containers/packaging/build/Microsoft.NET.Build.Containers.targets
Falling back to patching base and 3-way merge...
Auto-merging src/Containers/packaging/build/Microsoft.NET.Build.Containers.targets
CONFLICT (content): Merge conflict in src/Containers/packaging/build/Microsoft.NET.Build.Containers.targets
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Patch failed at 0001 make container app/entrypoint argument defaults only happen on the RID-specific builds, not the outer RID-less build
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!