(4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries

Mechanically generated by running this command:

tools_webrtc/do-renames.sh update all-renames.txt && git cl format

Then manually updating:

tools_webrtc/sanitizers/tsan_suppressions_webrtc.cc

Bug: webrtc:10159
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I54824cd91dada8fc3ee3d098f971bc319d477833
Reviewed-on: https://webrtc-review.googlesource.com/c/115653
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26226}

sdk/android/src/jni/android_video_track_source.cc

@@ -8,11 +8,11 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "sdk/android/src/jni/androidvideotracksource.h"
+#include "sdk/android/src/jni/android_video_track_source.h"
 
 #include <utility>
 
-#include "api/videosourceproxy.h"
+#include "api/video_track_source_proxy.h"
 #include "rtc_base/logging.h"
 
 namespace webrtc {