Add start tcpdump on data interfaces only.

Do not use tcpdump on any interface with "-i any" as it will break sl4a session.

Enable tcpdump in utilities after interface comes up as tcpdump has to start with UP interface.

Check internet connection after bring up Wifi.

test: run ACTS test
Bug: None
Change-Id: Ia6114027438364e9928d37c1d7d2b763b8a21549
diff --git a/acts/tests/google/tel/live/TelLiveStressTest.py b/acts/tests/google/tel/live/TelLiveStressTest.py
index 6ae94c1..c69b143 100644
--- a/acts/tests/google/tel/live/TelLiveStressTest.py
+++ b/acts/tests/google/tel/live/TelLiveStressTest.py
@@ -134,7 +134,7 @@
                     self.wifi_network_ssid,
                     self.wifi_network_pass,
                     retries=3):
-                ad.log.error("Phone Wifi connection fails.")
+                ad.log.error("Bringing up Wifi connection fails.")
                 return False
             ad.log.info("Phone WIFI is connected successfully.")
             if not set_wfc_mode(self.log, ad, WFC_MODE_WIFI_PREFERRED):