[material_ui] Migrate AppBar M3 template to use new gen_defaults script#12122

QuncCccccc merged 4 commits into

flutter:m3e_migrationflutter/packages:m3e_migrationfrom

QuncCccccc:app_bar_m3_defaults_migrationQuncCccccc/packages:app_bar_m3_defaults_migrationCopy head branch name to clipboard