Give x permission on apex data directories.

This gives search (x) permission on the parent apex data
directory /data/misc/apexdata so that directories below it
may be opened. It also gives that permission on the apex
data directories themselves.

Bug: 147848983
Test: Build & flash, check perms are correct
Change-Id: I27c4ea01602002c89d0771a144265e3879d9041a