Use default strides in allocated buffer in h264 encoder wrapper

The explicit values were incorrect: u/v strides were half-width rounded
down, but it has to be rounded up: for odd resolutions there are supposed to be extra u/v samples for last odd pixels.

Bug: chromium:542449805
Change-Id: I06f85d4cba737f69699f056057ebf039094bbffe
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/493940
Reviewed-by: Sergey Silkin <ssilkin@webrtc.org>
Auto-Submit: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#48298}

modules/video_coding/codecs/h264/h264_encoder_impl.cc

diff --git a/modules/video_coding/codecs/h264/h264_encoder_impl.cc b/modules/video_coding/codecs/h264/h264_encoder_impl.cc
index 69db6ff..0056291 100644
--- a/modules/video_coding/codecs/h264/h264_encoder_impl.cc
+++ b/modules/video_coding/codecs/h264/h264_encoder_impl.cc
@@ -335,9 +335,7 @@
     // Create downscaled image buffers.
     if (i > 0) {
       downscaled_buffers_[i - 1] = I420Buffer::Create(
-          configurations_[i].width, configurations_[i].height,
-          configurations_[i].width, configurations_[i].width / 2,
-          configurations_[i].width / 2);
+          configurations_[i].width, configurations_[i].height);
     }
 
     // Codec_settings uses kbits/second; encoder uses bits/second.