Improve testOpenConnection() reliability with fallback IPv6 check

Enhanced testOpenConnection() to include a fallback mechanism that
verifies the current IPv6 address via a DNS query if the initial HTTP
query check fails. This improves test reliability, particularly in
userdebug environments.

Bug: 325894686
Test: TH
Change-Id: I21a496eefd2b2c3d581755c363fedb6c5f9ca4a6
2 files changed