Refactor bitrate_controller, remote_bitrate_estimator and congestion_contoller for gn check.

These targets are now checked:
- "//webrtc/modules/bitrate_controller/*"
- "//webrtc/modules/congestion_controller/*"
- "//webrtc/modules/remote_bitrate_estimator/*"

BUG=webrtc:6828
NOTRY=True

Review-Url: https://codereview.webrtc.org/2602563003
Cr-Commit-Position: refs/heads/master@{#15818}

webrtc/modules/bitrate_controller/BUILD.gn

@@ -9,6 +9,11 @@
 import("../../build/webrtc.gni")
 
 rtc_static_library("bitrate_controller") {
+  # TODO(mbonadei): Remove (bugs.webrtc.org/6828)
+  # Errors on cyclic dependency with:
+  # congestion_controller:congestion_controller if enabled.
+  check_includes = false
+
   sources = [
     "bitrate_controller_impl.cc",
     "bitrate_controller_impl.h",
@@ -32,6 +37,8 @@ rtc_static_library("bitrate_controller") {
   }
 
   deps = [
+    "../../base:rtc_base_approved",
     "../../system_wrappers",
+    "../rtp_rtcp",
   ]
 }