Allow native shared libraries in ASEC containers

This change moves the native library handling earlier in the package
installation process so that it may be inserted into ASEC containers
before they are finalized in the DefaultContainerService.

Note that native libraries on SD card requires that vold mount ASEC
containers without the "noexec" flag on the mount point.

Change-Id: Ib34b1886bf6f94b99bb7b3781db6e9b5a58807ba