Do not *directly* package libbcc.so

Bug: http://b/28866258

Remove libbcc.so from the list of directly packaged modules.  64-bit
libbcc.so gets included as a dependency for the bcc executable (which is
a required package).  32-bit libbcc.so is no longer necessary on 64-bit
devices.

This change also removes 32-bit libLLVM.so from a 64-bit system image
(leading to a 13M reduction in Angler's system image on AOSP) and a
considerable reduction in build time.

Test: - Build all topics in this CL
      - RsTest (including the 32-bit ABI) and CTS tests pass on x86 and
        x86_64 emulators and Angler.

Change-Id: I10f07e322a615f37d6967b7c938635f544ddceff