Gallery refactor - Infer version from existing content (#32270)

* Give content precedence over flag in edit wrapper

This modifies the logic in the gallery edit wrapper function to infer
version information from existing content when the editor encounters
content created from the new implementation and the flag is not set.

packages/block-library/src/gallery/edit-wrapper.js

@@ -23,10 +23,15 @@ export default function GalleryEditWrapper( props ) {
 		return settings.__experimentalGalleryRefactor;
 	}, [] );
 
+	// This logic is used to infer version information from content with higher
+	// precedence than the flag. New galleries (and existing empty galleries) will
+	// honor the flag.
+	const hasNewVersionContent = !! attributes?.imageCount;
+	const hasOldVersionContent =
+		0 < attributes?.ids?.length || 0 < attributes?.images?.length;
 	if (
-		! __experimentalGalleryRefactor ||
-		attributes?.ids?.length > 0 ||
-		attributes?.images?.length > 0
+		hasOldVersionContent ||
+		( ! hasNewVersionContent && ! __experimentalGalleryRefactor )
 	) {
 		return <GalleryEditV1 { ...props } />;
 	}