Add Label() to archive_contents_test marco (#2618)

Since this macro is not specific to any test or target under test in
rule_apple, Label() helps resolve the script form externally defined
targets and tests.

There are many more uses of the `apple_verification_test` rule, but they
are specific internally and I chose not to add across the board.

test/starlark_tests/rules/common_verification_tests.bzl

@@ -221,7 +221,7 @@ def archive_contents_test(
             "TEXT_FILE_NOT_CONTAINS": text_file_not_contains,
         },
         target_under_test = target_under_test,
-        verifier_script = "//test/starlark_tests:verifier_scripts/archive_contents_test.sh",
+        verifier_script = Label("//test/starlark_tests:verifier_scripts/archive_contents_test.sh"),
         **kwargs
     )