modules/video_coding/utility: Remove include

This makes it clearer this code not meant to be used as an API.
I could not find any use of this in downstream code.

BUG=webrtc:5095
TESTED=git cl try -c --bot=android_compile_rel --bot=linux_compile_rel --bot=win_compile_rel --bot=mac_compile_rel --bot=ios_rel --bot=linux_gn_rel --bot=win_x64_gn_rel --bot=mac_x64_gn_rel --bot=android_gn_rel -m tryserver.webrtc
R=stefan@webrtc.org
TBR=magjed@webrtc.org

Review URL: https://codereview.webrtc.org/1440873005 .

Cr-Commit-Position: refs/heads/master@{#10699}
diff --git a/webrtc/modules/video_coding/BUILD.gn b/webrtc/modules/video_coding/BUILD.gn
index 609675f..cbfe8c0 100644
--- a/webrtc/modules/video_coding/BUILD.gn
+++ b/webrtc/modules/video_coding/BUILD.gn
@@ -94,14 +94,14 @@
 source_set("video_coding_utility") {
   sources = [
     "utility/frame_dropper.cc",
-    "utility/include/frame_dropper.h",
-    "utility/include/moving_average.h",
-    "utility/include/qp_parser.h",
-    "utility/include/quality_scaler.h",
-    "utility/include/vp8_header_parser.h",
+    "utility/frame_dropper.h",
+    "utility/moving_average.h",
     "utility/qp_parser.cc",
+    "utility/qp_parser.h",
     "utility/quality_scaler.cc",
+    "utility/quality_scaler.h",
     "utility/vp8_header_parser.cc",
+    "utility/vp8_header_parser.h",
   ]
 
   configs += [ "../..:common_config" ]