Now that we have sepolicy module in Android.bp, we can migrate contexts
tests. Also vendor_service_contexts_test will be run, as we now include
vendor_service_contexts unconditionally.
Unfortunately, vendor_service_contexts_test is now broken, due to a
malformed type hal_power_stats_vendor_service. We will temporarily
exempt the type from the test, to speed up migrating to Android.bp.
Bug: 33691272
Test: m selinux_policy and see tests running
Test: add a malformed type other than hal_power_stats_vendor_service and
run tests
Change-Id: Ic60eb38b9a7c79006f0b5ff4453768e03006604b
Because Android.bp is getting bigger and bigger.
Test: build and boot
Test: set OVERRIDE_TARGET_FLATTEN_APEX=true and build
Change-Id: I397ce084bfbc98449d177dd553ff73fdfbdddcaf
