And allow any SELinux domain to read these timezone
related files.

Addresses the following denial:
<5>[    4.746399] type=1400 audit(3430294.470:7): avc:  denied  { open } for  pid=197 comm="time_daemon" name="tzdata" dev="mmcblk0p28" ino=618992 scontext=u:r:time:s0 tcontext=u:object_r:system_data_file:s0 tclass=file

Change-Id: Iff32465e62729d7aad8c79607848d89ce0aede86