The hook/build.dart of packages should be able to not only add native code assets, but also data assets.

In Flutter, these data assets should be made available through the existing asset bundle API.

This issue tracks the flutter implementation for this in flutter tools.

• Add data_asset to BuildConfig.supportedAssetTypes.
• Bundle the [DataAsset]s from BuildOutput.assets in Flutter applications (on all 5 OSes, in all modes).
  • Open question: should asset contents be refreshed on hot reload / hot restart?

Tracking issue for Dart and Flutter combined:

• [native_assets_cli] data assets dart-lang/native#154

Umbrella issue for native assets:

• ☂️ Build hooks & Code assets #129757

cc @mosuem @andrewkolos @christopherfujino