Enable gsid to read /sys/fs/f2fs

gsid needs access to /sys/fs/f2fs/<dev>/features to detect whether
pin_file support is enabled in the kernel.

Bug: 134949511
Test: libsnapshot_test gtest
Change-Id: I5c7ddba85c5649654097aa51285d7fa5c53f4702
diff --git a/private/gsid.te b/private/gsid.te
index 306efb8..4771311 100644
--- a/private/gsid.te
+++ b/private/gsid.te
@@ -36,6 +36,10 @@
 # file names.
 r_dir_file(gsid, sysfs_dm)
 
+# libfiemap_writer needs to read /sys/fs/f2fs/<dev>/features to determine
+# whether pin_file support is enabled.
+r_dir_file(gsid, sysfs_fs_f2fs)
+
 # Needed to read fstab, which is used to validate that system verity does not
 # use check_once_at_most for sdcard installs. (Note: proc_cmdline is needed
 # to get the A/B slot suffix).