IWYU modules/audio_coding

using
  find modules/audio_coding -name "*.h" -o -name "*.cc" | | xargs tools_webrtc/iwyu/apply-include-cleaner
followed by
  tools_webrtc/gn_check_autofix.py -C out/Default/
followed by running clang-tidy with
  tools/clang/scripts/build_clang_tools_extra.py \
    --fetch out/Default clang-tidy clang-apply-replacements
  ninja -C out/Default
  gn gen out/Default --export-compile-commands
  cd out/Default
  tools/clang/third_party/llvm/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py -p . \
    -clang-tidy-binary out/Default/tools/clang/third_party/llvm/build/bin/clang-tidy \
    -clang-apply-replacements-binary \
        out/Default/tools/clang/third_party/llvm/build/bin/clang-apply-replacements \
    -checks='-*,modernize-deprecated-headers' \
    -fix modules/audio_coding
to move from C style standard headers to C++ style variants followed by
  git cl format
and git cl format.
Then IWYU again because it seems to understand C++ headers better than  C ones.

Manual fixes: include order in G711 and G722 unit tests

Bug: webrtc:42226242
Change-Id: Ie56ed311933ed629622da04fe51feee32acfcd2d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/395100
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Jakob Ivarsson‎ <jakobi@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@meta.com>
Cr-Commit-Position: refs/heads/main@{#45016}