Resolve some more lint attribute issues.
Resolve some more lint attribute issues.

apple/bundling/macos_rules.bzl:378: attr-single-file: single_file is deprecated in favor of allow_single_file. (https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#attr-single-file)
apple/bundling/macos_rules.bzl:384: attr-non-empty: non_empty attributes for attr definitions are deprecated in favor of allow_empty. (https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#attr-non-empty)

File fixed via `buildifier --lint=fix`

PiperOrigin-RevId: 225838436

bazelbuild/rules_apple,bazelbuild/rules_apple,bazelbuild/rules_apple,bazelbuild/rules_apple