flutter_desktop_darwin_unittests fails in AOT modes (profile and release) #66664
Description
When AOT fixtures are built in release/profile mode, flutter_desktop_darwin_unittests crashes with the following error:
[ERROR:flutter/runtime/dart_vm_data.cc(18)] VM snapshot invalid and could not be inferred from settings.
[ERROR:flutter/runtime/dart_vm.cc(249)] Could not setup VM data to bootstrap the VM from.
[ERROR:flutter/runtime/dart_vm_lifecycle.cc(84)] Could not create Dart VM instance.
[FATAL:flutter/shell/common/shell.cc(265)] Check failed: vm. Must be able to initialize the VM.
[ERROR:flutter/fml/backtrace.cc(110)] Caught signal SIGABRT during program execution.
We need to move the the FlutterDartProject initialization to conditionally check if the engine is in AOT mode. The fixture should generate the AOT assets already.
See flutter/engine#20531 (comment) and flutter/engine#21231 (comment)