chromeos_camera/MJDA: Fix unsynced mapped output frame in unit test

Use the VAAPI frame mapper instead of the linear frame mapper (i.e.
mmap()) to read the correctly synced output frame of MJDA.

Bug: 991136, b:120057531
Test: jpeg_decode_accelerator_unittest
Change-Id: Ibf3bee74176fa879a800bcd893ab9f222e65ebbb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1739306Reviewed-by: Ricky Liang <jcliang@chromium.org>
Commit-Queue: Ren-Pei Zeng <kamesan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#684317}

components/chromeos_camera/mjpeg_decode_accelerator_unittest.cc

@@ -562,7 +562,7 @@ void JpegClient::PrepareMemory(int32_t bitstream_buffer_id) {
         supported_formats[0], image_file->coded_size, image_file->visible_size);
     ASSERT_TRUE(hw_out_dmabuf_frame_);
     frame_mapper_ = media::VideoFrameMapperFactory::CreateMapper(
-        hw_out_dmabuf_frame_->format(), true);
+        hw_out_dmabuf_frame_->format());
     ASSERT_TRUE(frame_mapper_);
   } else {
     // MJDA only supports I420 format for SHM output buffer.