Improve data separation test coverage

Two areas need better coverage:
1. Tests are not verifying that files in /data/vendor do not have the
core_data_file_type attribute.
2. No error is thrown if a type lives in both /data/vendor
/data/<not vendor>.

Bug: 72998741
Test: build all selinux policies on master (assert build time tests)
Test: build and boot Marlin and Taimen, verify no selinux denials and
    everything works as expected.

Change-Id: I133a068123139a599b9b81ddcc254616894621eb
(cherry picked from commit 55d5e28472ad9cd87da0b451d78555d8aae43bb8)
diff --git a/tests/sepolicy_tests.py b/tests/sepolicy_tests.py
index ca95f8a..2cf4ae8 100644
--- a/tests/sepolicy_tests.py
+++ b/tests/sepolicy_tests.py
@@ -24,8 +24,8 @@
     return pol.AssertPathTypesHaveAttr(["/vendor/"], [], "vendor_file_type")
 
 def TestCoreDataTypeViolations(pol):
-    return pol.AssertPathTypesHaveAttr(["/data/"], ["/data/vendor/",
-            "/data/vendor_ce/", "/data/vendor_de/"], "core_data_file_type")
+    return pol.AssertPathTypesHaveAttr(["/data/"], ["/data/vendor",
+            "/data/vendor_ce", "/data/vendor_de"], "core_data_file_type")
 
 ###
 # extend OptionParser to allow the same option flag to be used multiple times.