[Cleanup] Add missing #include. Remove useless ones.

This CL is the result of running include-what-you-use tool on part
of the code base (audio target and dependencies) plus manual fixes.

bug: webrtc:8311
Change-Id: I277d281ce943c3ecc1bd45fd8d83055931743604
Reviewed-on: https://webrtc-review.googlesource.com/c/106280
Commit-Queue: Yves Gerey <yvesg@google.com>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25311}
diff --git a/api/rtp_headers.h b/api/rtp_headers.h
index 799058d..eff6223 100644
--- a/api/rtp_headers.h
+++ b/api/rtp_headers.h
@@ -12,6 +12,7 @@
 #define API_RTP_HEADERS_H_
 
 #include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
 #include "api/array_view.h"
@@ -19,7 +20,6 @@
 #include "api/video/video_frame_marking.h"
 #include "api/video/video_rotation.h"
 #include "api/video/video_timing.h"
-
 #include "common_types.h"  // NOLINT(build/include)
 
 namespace webrtc {