Remove VNDK related code from Soong

As VNDK definition is fully removed from Android.bp, VNDK related code
can be removed from Soong. This change removes VNDK related code except
VNDK prebuilt which is required to build former versions of VNDK APEX
with prebuilts.

Bug: 330100430
Test: AOSP CF build succeeded
Ignore-AOSP-First: Resolve Conflict
Change-Id: Id9c8993343221c8464c97296bde0ff40b14b9b0b