wifi_test_utils: add check for active tether

Add an explicit check for an entry in the active tether list for a
TETHER_STATE_CHANGE event.  Additionally add try...catch for missing
events.

BUG: 30800631
Change-Id: I217870c01feffcb49d7754985b5b75bac7de4d43
TEST: TelLiveDataTest:test_disable_wifi_tethering_resume_connected_wifi
(cherry picked from commit 21358801e9ea4a9a26915a61fdd93fc35eecd5ec)
1 file changed
tree: b773ece5d5b97a19f6685efeb56c29dbd274745d
  1. acts/