Re-enable dart runner AOT builds (#31844)

Fixed: fxbug.dev/64153

Note that I also removed the TODO for fxbug.dev/86941. After talking
with the bug author, this file is not directly relevant to that bug.

tools/fuchsia/dart/config.gni

@@ -5,19 +5,17 @@
 import("//flutter/tools/fuchsia/dart/dart_build_config.gni")
 
 declare_args() {
-  # TODO(fxbug.dev/86941) enable dart_runner_integration_tests
-  # TODO(fxbug.dev/64153) renable dart runner aot builds
-  # if (flutter_runtime_mode == "release") {
-  #   # Product AOT
-  #   dart_default_build_cfg = dart_release_build_cfg
-  # } else if (flutter_runtime_mode == "jit_release") {
-  #   # Product JIT
-  #   dart_default_build_cfg = dart_jit_release_build_cfg
-  # } else if (flutter_runtime_mode == "debug") {
-  # Non-product JIT
-  dart_default_build_cfg = dart_debug_build_cfg
-  # } else { # "profile"
-  #   # Non-product AOT
-  #   dart_default_build_cfg = dart_profile_build_cfg
-  # }
+  if (flutter_runtime_mode == "release") {
+    # Product AOT
+    dart_default_build_cfg = dart_release_build_cfg
+  } else if (flutter_runtime_mode == "jit_release") {
+    # Product JIT
+    dart_default_build_cfg = dart_jit_release_build_cfg
+  } else if (flutter_runtime_mode == "debug") {
+    # Non-product JIT
+    dart_default_build_cfg = dart_debug_build_cfg
+  } else {  # "profile"
+    # Non-product AOT
+    dart_default_build_cfg = dart_profile_build_cfg
+  }
 }