Fix constraints on GetInfo response

Currently, FIDO devices that sends any other protocols other than
'FIDO_2_0' or 'U2F_V2'in response to GetInfo command is rejected. This
constraint needs to be fixed so that while devices that send duplicate or empty
protocol list should be rejected, any protocols that the client does not
know should be ignored.

Change-Id: I0a574ada22d621e891c99d313eb19c3648144638
Reviewed-on: https://chromium-review.googlesource.com/1153620
Commit-Queue: Jun Choi <hongjunchoi@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579205}

device/fido/device_response_converter.cc

@@ -169,8 +169,8 @@ base::Optional<AuthenticatorGetInfoResponse> ReadCTAPGetInfoResponse(
 
     auto protocol = ConvertStringToProtocolVersion(version.GetString());
     if (protocol == ProtocolVersion::kUnknown) {
-      DLOG(ERROR) << "Unexpected protocol version received.";
-      return base::nullopt;
+      VLOG(2) << "Unexpected protocol version received.";
+      continue;
     }
 
     if (!protocol_versions.insert(protocol).second)