PicoIMX: Fix file permissions, SELinux policy.

-Several text files had executable permissions. Remove the +x.
-Some domains are attempting to load kernel modules (which is
not allowed in Brillo), resulting in several denials like:
"""
denied { module_request } for kmod="personality-8" scontext=u:r:init:s0
  tcontext=u:r:kernel:s0 tclass=system
"""

Stop auditing these denials to make it easier to diagnose real SELinux
issues.

-'allow mediaserver debug_prop:property_service set;' is not needed.

Bug: 27249509
Change-Id: Iced4d96b63bb100f5b7ec27b08cbf14d884e65df
12 files changed