Let DCS read staged APK clusters.

DCS is DefaultContainerService.

avc: denied { getattr } for path="/data/app/vmdl2.tmp"
    dev="mmcblk0p28" ino=162910 scontext=u:r:platform_app:s0
    tcontext=u:object_r:apk_tmp_file:s0 tclass=dir

Bug: 14975160
Change-Id: Ifca9afb4e74ebbfbeb8c01e1e9ea65f5b55e9375