Include module_common_types.h only where needed

Bug: None
Change-Id: I73d493f8f186b429c7be808f4dfac0398f150931
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/153891
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29277}

modules/video_coding/timing.h

@@ -13,6 +13,8 @@
 
 #include <memory>
 
+#include "absl/types/optional.h"
+#include "api/video/video_timing.h"
 #include "modules/video_coding/codec_timer.h"
 #include "rtc_base/critical_section.h"
 #include "rtc_base/thread_annotations.h"