[bug]: Venia storefront not accessible on cloud starter. Cause PR #1498

[dpatil-magento]

Describe the bug
On accessing venia on storefront getting exception.
Build on commit - 4db08e0 #1498

To Reproduce

1. Deploy build on commit 4db08e0 to cloud env.
2. Access venia storefront. Check with @dpatil-magento for the env to reproduce.

Expected behavior
Venia home page should load.

Actual
Fatal error: Uncaught TypeError: file_get_contents() expects parameter 1 to be a valid path, bool given in /app/vendor/magento/upward/src/Resolver/File.php:94 Stack trace: #0 /app/vendor/magento/upward/src/Resolver/File.php(94): file_get_contents(false) #1 /app/vendor/magento/upward/src/DefinitionIterator.php(208): Magento\Upward\Resolver\File->resolve('./asset-manifes...') #2 /app/vendor/magento/upward/src/DefinitionIterator.php(186): Magento\Upward\DefinitionIterator->getFromResolver('assetManifest', './asset-manifes...', Object(Magento\Upward\Resolver\File)) #3 /app/vendor/magento/upward/src/DefinitionIterator.php(99): Magento\Upward\DefinitionIterator->getFromDefinedValue('assetManifest', './asset-manifes...') #4 /app/vendor/magento/upward/src/Resolver/Template.php(60): Magento\Upward\DefinitionIterator->get('assetManifest') #5 /app/vendor/magento/upward/src/DefinitionIterator.php(208): Magento\Upward\Resolver\Template->resolve(Object(Magento\Upward\Definition)) #6 /app/vendor/magento/upward/src/DefinitionIterator.php in /app/vendor/magento/upward/src/Resolver/File.php on line 94

Additional context

1. This is broken as part of V4P2: feat(buildpack): Add Webpack configurator facade #1498. Confirmed by deploying Updates alias to avoid collisions #1522 which got merged before V4P2: feat(buildpack): Add Webpack configurator facade #1498.
2. If we revert below changes of upward.yml file then storefront works fine but might break something on upward-js side.
   assetManifest: ./asset-manifest.json to assetManifest: ./dist/asset-manifest.json
   bundles inline: '.' to inline: './dist'
inline: './static' to inline: './dist/static'
veniaTemplateIncludes: './templates' to veniaTemplateIncludes: './dist/templates'

[dpatil-magento]

We need to pass upward.yml file path of dist folder.