Reenables usb on 0.7+ host images

Bug: 111311516
Test: local run with unstable tools, 0.7pre3 on gce with two pi-gce-dev
devices with --adb_mode=usb

Change-Id: I649f331b94e6a77e2b32012f847e1945666f6acd
diff --git a/host/libs/vm_manager/cf_qemu.sh b/host/libs/vm_manager/cf_qemu.sh
old mode 100644
new mode 100755
index c93281c..69a8c5e
--- a/host/libs/vm_manager/cf_qemu.sh
+++ b/host/libs/vm_manager/cf_qemu.sh
@@ -87,6 +87,12 @@
   args+=(-initrd "${ramdisk_image_path}")
 fi
 
+if [[ -n "${usb_v1_socket_name}" ]]; then
+  args+=(
+      -chardev "socket,id=charchannel1,path=${usb_v1_socket_name:-${default_dir}/usb-v1}"
+      -device "virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel1,id=channel1,name=cf-gadget-usb-v1"
+  )
+fi
 printf %s "exec ${qemu_binary=/usr/bin/qemu-system-x86_64}"
 for i in "${args[@]}"; do
   case "$i" in