charger: allow to read /sys/class/power_supply

Test: charger mode correctly shuts off when unplugged

Change-Id: I06a7ffad67beb9f6d9642c4f53c35067b0dc2b3d
Fixes: 71328882

public/charger.te

@@ -6,10 +6,12 @@ type charger, domain;
 allow charger kmsg_device:chr_file rw_file_perms;
 
 # Read access to pseudo filesystems.
-allow charger sysfs_type:dir search;
 r_dir_file(charger, rootfs)
 r_dir_file(charger, cgroup)
 
+# Allow to read /sys/class/power_supply directory
+allow charger sysfs_type:dir r_dir_perms;
+
 allow charger self:global_capability_class_set { sys_tty_config };
 allow charger self:global_capability_class_set sys_boot;