Changes:
- Rename flutter-gallery bbappend to handle switch to BBCLASSEXTEND
scheme in the upstream recipe.
- Update the Flutter embedder package name in the Flutter demo image
package group to handle upstream change.
Bug-AGL: SPEC-4485
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: I3d5cf4e6f38b766c5dc65979cb53b6674af2b03a