Retrieve statistics about the content of the build, such as total sizes, object counts, and breakdowns by Unity Object type and source Asset.
ContentSummary is populated for Player builds, AssetBundle builds, and ContentDirectory builds.
It is not populated for scripts-only Player builds (see BuildOptions.BuildScriptsOnly).
For incremental AssetBundle builds, the statistics only reflect the AssetBundles that were
rebuilt in the current build invocation; unchanged AssetBundles reused from previous builds
are not included.
This property returns null if the ContentSummary was not populated.
Additional resources: ContentSummary