Make shill and flimflam Ignore pseudomodem0p on test builds

Make shill and flimflam ignore pseudomodem0p on test builds so that
the network devices called pseudomodem0p can be used to test the
cellular classes of shill on virtual machines.

BUG=none
TEST=run network_3GModemControl on a vm
Change-Id: I61cc89d114dcb82bb01b864b68f220fbaf21509d
Reviewed-on: https://gerrit.chromium.org/gerrit/23059
Commit-Ready: Jason Glasgow <jglasgow@chromium.org>
Reviewed-by: Jason Glasgow <jglasgow@chromium.org>
Tested-by: Jason Glasgow <jglasgow@chromium.org>
diff --git a/mod_for_test_scripts/100setupTestingInterface b/mod_for_test_scripts/100setupTestingInterface
index cc3bb24..94b9ad2 100755
--- a/mod_for_test_scripts/100setupTestingInterface
+++ b/mod_for_test_scripts/100setupTestingInterface
@@ -7,12 +7,13 @@
 echo "Configuring for backchannel network device"
 
 testif=eth_test
+modemif=pseudomodem0p
 
 # Prevent flimflam from taking control of the backchannel network device.
 ORIG_CONF=${ROOT_FS_DIR}/etc/init/flimflam.conf
 TEMP_CONF=${ORIG_CONF}.tmp
-sed -e "s,flimflamd,flimflamd -I ${testif}," \
-    -e "s,SHILL_TEST_ARGS=\"\",SHILL_TEST_ARGS=\"--device-black-list=${testif}\"," \
+sed -e "s,flimflamd,flimflamd -I ${testif} -I ${modemif}," \
+    -e "s@SHILL_TEST_ARGS=\"\"@SHILL_TEST_ARGS=\"--device-black-list=${testif},${modemif}\"@" \
     ${ORIG_CONF} > ${TEMP_CONF}
 mv -f ${TEMP_CONF} ${ORIG_CONF}