Set BUILD_BROKEN_VENDOR_PROPERTY_NAMESPACE for goldfish

device/generic/goldfish/sepolicy/common/property_contexts still contains
violations, so temporarily setting build_broken to relax vendor property
check.

Bug: 176210699
Test: m vendor_property_contexts
Change-Id: Ia7d7830a7e994fd0766fd8854524bb6f9fa5cce6