Allow all domains to read /proc/sys/vm/overcommit_memory

glibc malloc read this file since commit 9fab36eb
(https://sourceware.org/git/?p=glibc.git;a=commit;h=9fab36eb)

Patch adapted from commit 343c0887514718387f36ee8ead2b941ba9bfb894
on fedora selinux-policy made by Dan Walsh <dwalsh@redhat.com>