intial centos(el8) support added

Server/config/EL8/mongodb.te

@@ -0,0 +1,12 @@
+module mongodb_cgroup_memory 1.0;
+
+require {
+    type cgroup_t;
+    type mongod_t;
+    class dir search;
+    class file { getattr open read };
+}
+
+#============= mongod_t ==============
+allow mongod_t cgroup_t:dir search;
+allow mongod_t cgroup_t:file { getattr open read };