Reland "heif: Add AVIF type and AVIF sniffing"

Fix: Do not use std::optional.

Bug: b/141654151
Change-Id: I6237db0d55b1ea92f7be3588a2b648b9e6014e3f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/331878
Reviewed-by: Vignesh Venkatasubramanian <vigneshv@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
diff --git a/RELEASE_NOTES.txt b/RELEASE_NOTES.txt
index a3d8c8f..3ab88a3 100644
--- a/RELEASE_NOTES.txt
+++ b/RELEASE_NOTES.txt
@@ -9,6 +9,8 @@
 
   * <insert new release notes here>
 
+  * Add AVIF support to SkHeifCodec.
+
   * Add support for creating SkSurfaceCharacterizations directly for use by a
     GrVkSecondaryCBDrawContext.
     https://review.skia.org/331877