bootanim: add selinux support to read extcon files

Add support for read_dir and reading Linux kernel extcon files.

Bug: 376854710
Test: No runtime avc denials for bootanim.
Change-Id: I1558674aedcb8c5b7db71f759e633dcfa6656d88
diff --git a/private/bootanim.te b/private/bootanim.te
index fd3a09b..8c48ed3 100644
--- a/private/bootanim.te
+++ b/private/bootanim.te
@@ -66,4 +66,8 @@
 allow bootanim system_file:dir r_dir_perms;
 
 # Allow bootanim to send information to statsd socket.
-unix_socket_send(bootanim, statsdw, statsd)
\ No newline at end of file
+unix_socket_send(bootanim, statsdw, statsd)
+
+# Allow bootanim to access extcon information.
+allow bootanim sysfs_extcon:dir r_dir_perms;
+allow bootanim sysfs_extcon:file r_file_perms;