Relocate VNDK-SP to /system/lib/vndk-sp and add RS libs to VNDK-SP

VNDK-SP is relocated back to /system partition from /vendor partition,
following the original design.

In addition, the namespace for RenderScript is added. The namespace is
dedicated for loading VNDK-SP libs for RenderScript such as
libRS_internal.so. The reason for having a separate namespace is that
RenderScript requires more permitted paths (/data/*) which should not be
allowed for normal SP-HALs.

Bug: 37522144
Bug: 37550338
Test: sailfish builds and boots well
Test: lsof shows VNDK-SP libs are loaded from /system/lib/vndk-sp
Test: RenderScript app (CameraScript) runs well
Change-Id: Id139f626cafae2e43ee4eefc5a57a204e31bbbc9