CopyAcrImages command attempts to import image tags marked as IsLocal

[mthalman]

When a tag in the manifest is marked as IsLocal, it means that tag will not be pushed when running the Build command with the --push option. When the CopyAcrImages command is then executed later on, it needs to then check whether the tag its attempting to import is marked as IsLocal. If it is, that tag won't exist in the source registry; so there's nothing to import. It should just skip any tags marked as IsLocal. By not skipping such tags, it just causes failures when running the import operation because the tag doesn't exist.

[MichaelSimons]

There aren't any usages that encounter this issue today.

[mthalman]

[Triage] This is relevant today because of some Dockerfile patterns that we've wanted to use in the https://github.com/dotnet/dotnet-buildtools-prereqs-docker repo. For example, there was a desire to have a "builder" Dockerfile that would be built locally only and shared by other multi-stage Dockerfiles. But due to limitations like this, it was required to be set with IsLocal being false.