mf/tests: Increase the H264 decoder tests video frame size.

mf/tests: Increase the H264 decoder tests video frame size.

GStreamer vaapi decoder suffers from bugs which are causing double frees
when the frame size is too small.

Test file has been generated with:

gst-launch-1.0 videotestsrc num-buffers=60 ! \
  video/x-raw,format=I420,width=82,height=84,framerate=30000/1001 ! \
  videoconvert ! x264enc ! filesink location=dlls/mf/tests/h264data.bin

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45988
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=47084
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=49715
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52183
Signed-off-by: Rémi Bernon <rbernon@codeweavers.com>
Signed-off-by: Nikolay Sivov <nsivov@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>