Increase the LISTEN_ACTIVITY_TIMEOUT_MS timer

The test reuqires WiFi becomes the default network. But in
some bad networks, the probing time may take more than the
existing timer(5s). Increase it to 30s to prevent flakes
causing by bad network.

Fix: 313372234
Test: atest CtsNetTestCases
Change-Id: Ie0d2f014d2551826596d4a0e28448ba129f5e9eb