Settings: Don't set root access as a default fallback option.

Problem: if persist.sys.root_access is not present, it will
set root access anyways regardless of build type
flaw: user build is not shipping root.
fix: set to 0 anyway which is no root.

Change-Id: I3d1e59042ec9d28a70bbc11d0c5d9f0ec0a0bcfb