Suppress power_supply access inside microdroid

Bug: 193118220
Test: atest MicrodroidHostTestCases
Change-Id: I3dbdcb831c61e9bd24cfdaa10beba9e856e605af
diff --git a/microdroid/system/private/shell.te b/microdroid/system/private/shell.te
index fc51ad8..3bb879d 100644
--- a/microdroid/system/private/shell.te
+++ b/microdroid/system/private/shell.te
@@ -29,3 +29,7 @@
 # filesystem test for insucre blk_file's is done
 # via hostside test
 allow shell dev_type:blk_file getattr;
+
+# Test tool automatically tries to access /sys/class/power_supply.
+# Suppressing it as we don't need power_supply in microdroid.
+dontaudit shell sysfs:dir r_dir_perms;