Update default parameters in screenshare_loopback test

webrtc/video/screenshare_loopback.cc

Index: webrtc/video/screenshare_loopback.cc
diff --git a/webrtc/video/screenshare_loopback.cc b/webrtc/video/screenshare_loopback.cc
index 91002ef9043484f0b82b8b650e35ee3c617d0d00..912aaaddc45ff7a163a461cd04a02a102ea9d7be 100644
--- a/webrtc/video/screenshare_loopback.cc
+++ b/webrtc/video/screenshare_loopback.cc
@@ -41,12 +41,14 @@ int MinBitrateKbps() {
   return static_cast<int>(FLAGS_min_bitrate);
 }
 
-DEFINE_int32(start_bitrate, 200, "Call start bitrate in kbps.");
+DEFINE_int32(start_bitrate,
+             Call::Config::kDefaultStartBitrateBps / 1000,
+             "Call start bitrate in kbps.");
 int StartBitrateKbps() {
   return static_cast<int>(FLAGS_start_bitrate);
 }
 
-DEFINE_int32(target_bitrate, 2000, "Stream target bitrate in kbps.");
+DEFINE_int32(target_bitrate, 200, "Stream target bitrate in kbps.");
 int TargetBitrateKbps() {
   return static_cast<int>(FLAGS_target_bitrate);
 }