Revert "Revert "Enable ADVANCED_VPN_ENABLED For Droidfood""

This reverts commit ecd21b73.

Reason for revert:

1. The original revert does not solve flaky test failure, still saw similar new bugs. For example: b/275474028, b/270612944 and b/268326421.
2. The flag has nothing to do with the failed tests.

Change-Id: I8dd069d0c4af3469ad29a221c9c706856e577d48