Enable cpplint for webrtc/modules/bitrate_controller and fix all uncovered cpplint errors.

This CL enableds cpplint for webrtc/modules/bitrate_controller.

BUG=webrtc:5311
NOTRY=true

TESTED=Fixed issues reported by:
find webrtc/modules/bitrate_controller -type f -name *.cc -o -name *.h | xargs cpplint.py
followed by 'git cl presubmit'.

Review URL: https://codereview.webrtc.org/1620003003

Cr-Commit-Position: refs/heads/master@{#11363}
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc b/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
index fd9636a..3f467ef 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
@@ -8,11 +8,11 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "testing/gtest/include/gtest/gtest.h"
-
 #include <algorithm>
 #include <vector>
 
+#include "testing/gtest/include/gtest/gtest.h"
+
 #include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"