Cleanup vendor projects are proprietary.

Test: m droid dist
Change-Id: I0bdec38c4d12710fa97b91665d211ba6c0d4b24d

libwvdrmengine/vts/vendor_module/Android.bp

@@ -26,6 +26,7 @@ package {
     // to get the below license kinds:
     //   SPDX-license-identifier-Apache-2.0
     //   legacy_by_exception_only (by exception only)
+    //   legacy_proprietary (by exception only)
     default_applicable_licenses: ["vendor_widevine_license"],
 }