Integrate webRTC with the rest of the cuttlefish host elements

Call webRTC from the launcher based on launcher flag
Ensure only one streamer is enabled (vnc vs webrtc)
Break webrtc's dependencies on vsoc

Bug: 143713267
Test: launch_cvd -start_webrtc=true -start_vnc_server=false -webrtc_public_ip=127.0.0.1 --webrtc_certs_dir=$(pwd)/host/frontend/gcastv2/webrtc/certs --x_res=720 --y_res=1440 --webrtc_assets_dir=$(pwd)/host/frontend/gcastv2/webrtc
Change-Id: I35787c6541f64a0cf91fc81a215923b5f30163c7
diff --git a/host/frontend/gcastv2/webrtc/webRTC.cpp b/host/frontend/gcastv2/webrtc/webRTC.cpp
index 6e38333..6d7fce8 100644
--- a/host/frontend/gcastv2/webrtc/webRTC.cpp
+++ b/host/frontend/gcastv2/webrtc/webRTC.cpp
@@ -35,6 +35,8 @@
 
 DEFINE_int32(touch_fd, -1, "An fd to listen on for touch connections.");
 DEFINE_int32(keyboard_fd, -1, "An fd to listen on for keyboard connections.");
+DEFINE_int32(frame_server_fd, -1, "An fd to listen on for frame updates");
+DEFINE_bool(write_virtio_input, false, "Whether to send input events in virtio format.");
 
 DEFINE_string(adb, "", "Interface:port of local adb service.");
 #endif