Merge changes I3073efe9,I3b0f06e3,I4ca80033,I3bc23fd4,I327a085d, ...

* changes:
  vndk-def: Add GenericRefs.classify_lib().
  vndk-def: Link imported symbols.
  vndk-def: Add vndk-stable finder.
  vndk-def: Extract sp-hal finder.
  vndk-def: Return ELFLinkData for unit test.
  vndk-def: Refactor BannedLibDict and add unittests.
  vndk-def: Separate SP-NDK from HL-NDK.