Moves the code for transforming an unversioned module into a
versioned module into a transformer.
This is preparation for enhancing the versioning tranformer to support
applying per property transformations. Specifically, to allow
properties to reference other libraries within the sdk.
Bug: 142940300
Test: m nothing
Change-Id: Ia6b5cff8e1b5cd7232e031769d9fc0019e815fcb