Add support for no-vendor-variant VNDK

When no-vendor-variant VNDK is enabled, the vendor variant of VNDK
libraries are not installed.  Since not all VNDK libraries will be
ready for this, we keep a list of library names in cc/vndk.go to
indicate which libraries must have their vendor variants always
installed regardless of whether no-vendor-variant VNDK is enabled.

Also add --remove-build-id option to the strip script to facilitate
the check of functional identity of the two variants.

Bug: 119423884
Test: Add a dummy VNDK library and build with
      TARGET_VNDK_USE_CORE_VARIANT := true, with the corresponding
      build/make change.

Change-Id: Ieb1589488690e1cef1e310669a8b47a8b8759dac