Do not mark_as_advanced AMENT_VENDOR_POLICY

Author: traversaro

ament_cmake_vendor_package/cmake/ament_vendor.cmake

@@ -125,7 +125,6 @@ macro(ament_vendor TARGET_NAME)
   set(_AMENT_VENDOR_POLICY_DOCS "Specify how ament_vendor behaves, allowed values are DEFAULT, FORCE_BUILD_VENDOR, NEVER_VENDOR and NEVER_VENDOR_IGNORE_SATISFIED_CHECK.")
   set(AMENT_VENDOR_POLICY "DEFAULT" CACHE STRING ${_AMENT_VENDOR_POLICY_DOCS})
   set_property(CACHE AMENT_VENDOR_POLICY PROPERTY STRINGS "DEFAULT" "FORCE_BUILD_VENDOR" "NEVER_VENDOR" "NEVER_VENDOR_IGNORE_SATISFIED_CHECK")
-  mark_as_advanced(AMENT_VENDOR_POLICY)
 
   if(FORCE_BUILD_VENDOR_PKG AND NOT AMENT_VENDOR_POLICY STREQUAL "FORCE_BUILD_VENDOR")
     message(DEPRECATION "FORCE_BUILD_VENDOR_PKG set to ON detected, FORCE_BUILD_VENDOR_PKG variable is deprecated, please set AMENT_VENDOR_POLICY to FORCE_BUILD_VENDOR instead.")