fix flutter/flutter#107091

On the Android platform, the current implementation is that multiple lightweight engines share the same AssetManager, and the relationship between the engine and the AssetManager is Nv1. After engine restart, each engine will regenerate its own AssetManager, and the relationship between the engine and the AssetManager becomes 1v1.

Due to the following code, only one of these new AssetManagers will hold the original APKAssetProvider.
https://github.com/flutter/engine/blob/main/shell/common/shell.cc#L1632-L1641

  // Preserve any original asset resolvers to avoid syncing unchanged assets
  // over the DevFS connection.
  auto old_asset_manager = engine_->GetAssetManager();
  if (old_asset_manager != nullptr) {
    for (auto& old_resolver : old_asset_manager->TakeResolvers()) {
      if (old_resolver->IsValidAfterAssetManagerChange()) {
        configuration.AddAssetResolver(std::move(old_resolver));
      }
    }
  }

proposed solution

1. Lightweight engines no longer share AssetManager, each engine has own AssetManager, and each AssetManager has an APKAssetProvider inside.

2. There is an APKAssetProviderImpl inside the APKAssetProvider, which is used to encapsulate the specific implementation. In a lightweight engine scenario, multiple APKAssetProviders share the same APKAssetProviderImpl

3. APKAssetProvider provides a Clone method to create a new APKAssetProvider, the new provider shares APKAssetProviderImpl with the current provider.

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] and the [C++, Objective-C, Java style guides].
• I listed at least one issue that this PR fixes in the description above.
• I added new tests to check the change I am making or feature I am adding, or Hixie said the PR is test-exempt. See [testing the engine] for instructions on
  writing and running engine tests.
• I updated/added relevant documentation (doc comments with ///).
• I signed the [CLA].
• All existing and new tests are passing.