Reverts: #169273

Initiated by: jason-simmons

Reason for reverting: seeing flakes of dart_data_asset_test.dart

CI runs for various PRs got errors in the tool_integration_tests shards. The errors occurred on multiple platforms (Linux, Mac, and Windows).

Affected PRs include: #170022, #169995

LUCI log of an error:
https://ci.chromium.org/ui/p/flutter/builders/try/Windows%20t

Original PR Author: mosuem

Reviewed By: {bkonyi}

This change reverts the following previous change:
Refiling of #164094, which itself is a rebase of #159675

This PR adds bundling support for the experimental dart data asset feature: Dart packages with hooks can now emit data assets which the flutter tool will bundle.

It relies on flutter's existing asset bundling mechanism (e.g. entries in AssetManifest.json, DevFS syncing in reload/restart, ...).

The support is added under an experimental flag (similar to the existing native assets experimental flag).

Also, kNativeAssets is removed to also bundle data assets on flutter build bundle.

The chrome sandbox is disabled as per #165664.

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• I followed the breaking change policy and added Data Driven Fixes where supported.
• All existing and new tests are passing.

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