Update WifiTelCoexTest.py to reflect change where ensure_phones_idle() got moved to tel_phone_setup_utils.py.

CL where change was made: https://googleplex-android.git.corp.google.com/platform/tools/test/connectivity/+/44b04be53db2e0bd4a0afad7bdc0b2cee94243fe

Bug: 209525692
Change-Id: I77297265d689fb9c54edc688f09cc40fa10f967a
diff --git a/acts_tests/tests/google/wifi/WifiTeleCoexTest.py b/acts_tests/tests/google/wifi/WifiTeleCoexTest.py
index 73b6bb8..02e9541 100644
--- a/acts_tests/tests/google/wifi/WifiTeleCoexTest.py
+++ b/acts_tests/tests/google/wifi/WifiTeleCoexTest.py
@@ -16,6 +16,7 @@
 from acts_contrib.test_utils.tel.tel_ims_utils import toggle_volte
 from acts_contrib.test_utils.tel.tel_ims_utils import set_wfc_mode
 from acts_contrib.test_utils.tel.tel_phone_setup_utils import phone_setup_voice_general
+from acts_contrib.test_utils.tel.tel_phone_setup_utils import ensure_phones_idle
 from acts_contrib.test_utils.tel.tel_voice_utils import two_phone_call_short_seq
 from acts_contrib.test_utils.tel.tel_voice_utils import is_phone_in_call_iwlan
 from acts_contrib.test_utils.tel.tel_phone_setup_utils import phone_idle_iwlan
@@ -70,7 +71,7 @@
         for ad in self.android_devices:
             wifi_utils.reset_wifi(ad)
             ad.droid.telephonyToggleDataConnection(False)
-        tele_utils.ensure_phones_idle(self.log, self.android_devices)
+        ensure_phones_idle(self.log, self.android_devices)
         nutil.stop_usb_tethering(self.dut)
 
     """Helper Functions"""