Record netd_stable_secret_prop in compat infra.

Commit: abb1ba65 added policy for a
new property, which was not present in O.  This policy introduced a
new type.  Record it as such.

Bug: 62573845
Test: None, prebuilt change only.
Change-Id: I7d90cd69a5e6e29677598cc109676d5b1ce5ba05

prebuilts/api/26.0/26.0.ignore.cil

@@ -6,6 +6,7 @@
   ( e2fs
     e2fs_exec
     kmsg_debug_device
+    netd_stable_secret_prop
     sysfs_fs_ext4_features
     timezone_service
     tombstoned_java_trace_socket))