Add TARGET_OUT_VENDOR_RENDERSCRIPT_BITCODE definition.

 - TARGET_OUT_VENDOR_RENDERSCRIPT_BITCODE is the output directory of
 RENDERSCRIPT_BITCODE (libclcore.bc) for vendors.
 - It is only used if LOCAL_PROPRIETARY_MODULE := true specified for the
 bitcode module.

Bug: 34396220
Bug: 34334222
Test: mm
Change-Id: I10237470eff0d8a693ce73313944e9b24595c5b7