Add no_x_file_perm to property related files.

It doesn't ever make sense to attempt to load executable code
from these files. Add a neverallow rule (compile time assertion and
CTS test).

Bug: 27882507

(cherry picked from commit 50ba6318)

Change-Id: Ifab6e46a077a87629b4d3c7ada1050f2ab6931d5