Revert "Take all VPN underlying networks into account when migrating traffic for"

This reverts commit 917327b1933c6edc8314fe728e5f14f6e29dd5f4.

Reason for revert: This change has been implicated in 4-way deadlocks as seen in b/134244752.

Bug: 134244752
Change-Id: Ibdaad3a4cbf0d8ef1ed53cfab1e454b9b878bae9
7 files changed