gogole-usb: add option to not bridge the usb link

Google-Bug-Id: 543188543
Platforms-Affected: bloom
Tested: verified on mimik that the link is not bridged.
Change-Id: I5148f4aee99410c020545db60052e3e7cae2e08f
Signed-off-by: Yuxiao Zhang <yuxiaozhang@google.com>
(cherry picked from commit 649e144242b127a1fca3298cbceaa60dc04fc40a)

recipes-google/networking/google-usb-network/google-usb-dynamic.cpp

diff --git a/recipes-google/networking/google-usb-network/google-usb-dynamic.cpp b/recipes-google/networking/google-usb-network/google-usb-dynamic.cpp
index c92a2e0..7b5e8d2 100644
--- a/recipes-google/networking/google-usb-network/google-usb-dynamic.cpp
+++ b/recipes-google/networking/google-usb-network/google-usb-dynamic.cpp
@@ -219,6 +219,7 @@
     add("--dev-mac", "DevMac", /*required=*/false);
     add("--host-mac", "HostMac", /*required=*/false);
     add("--iface-alias", "IfAlias", /*required=*/false);
+    add("--no-bridge", "NoBridge", /*required=*/false);
 
     auto pn = props.find("IFName");
     std::string ifname;