meta-agl-demo uses meta-flutter bbclass w/o depending on it

meta-agl-demo dependencies:
https://gerrit.automotivelinux.org/gerrit/gitweb?p=AGL/meta-agl-demo.git;a=blob;f=conf/layer.conf;hb=HEAD
LAYERDEPENDS_agldemo = "aglcore qt5-layer openembedded-layer"

but flutter apps do inherit flutter-app.bbclass, e.g.:
https://gerrit.automotivelinux.org/gerrit/gitweb?p=AGL/meta-agl-demo.git;a=blob;f=recipes-demo/flutter-hvac/flutter-hvac_git.bb;hb=HEAD