meta-agl-flutter refactor

meta-agl-flutter refactor

- application rename -> flutter-auto

- adopts upstream (meta-flutter) bbclass for runtime selection
  runtimedebug -> runtime=debug
  runtimeprofile -> runtime=profile
  runtimerelease -> runtime=release
  *This also affects image names*

- A discrete json files for each runtime configuration
  demuxing of runtime config happens in bbappend.

- prevent dev host conflict with flutter-auto.service in case
  of debug and profile.  The dev host machine controls
  homescreen in these scenarios.

- simplifies inc and recipes

Dependent on https://gerrit.automotivelinux.org/gerrit/c/AGL/AGL-repo/+/27850

Bug-AGL: SPEC-4326

Signed-off-by: Joel Winarske <joel.winarske@gmail.com>
Change-Id: I877811417e3befab4d48a906058dcb52c81be4ce