Add target_arch to vndk prebuilt module name

To distinguish libfoo.vndk.$VER prebuilts of various
vndk_v$VER_$ARCH phony package modules, append $ARCH to the
LOCAL_MODULE name for VNDK prebuilts.
e.g. libfoo.vndk.$VER becomes libfoo.vndk.$VER.$ARCH

Test: m -j PRODUCT_EXTRA_VNDK_VERSIONS=27
Bug: 71370248
Change-Id: I3e9ebd929111ceb48e362c500adfb4b7a94444e8