Restrict kernel keyring search capability

The original use case has already been deprecated.

Test: TH
Bug: 384942085
Change-Id: Icc01be819b89a2b2da23c601f393660cd042a771
diff --git a/flagging/Android.bp b/flagging/Android.bp
index c92991f..b9cef64 100644
--- a/flagging/Android.bp
+++ b/flagging/Android.bp
@@ -31,6 +31,7 @@
         "RELEASE_HARDWARE_BLUETOOTH_RANGING_SERVICE",
         "RELEASE_UNLOCKED_STORAGE_API",
         "RELEASE_BLUETOOTH_SOCKET_SERVICE",
+        "RELEASE_SEPOLICY_RESTRICT_KERNEL_KEYRING_SEARCH",
     ],
     export_to: ["all_selinux_flags"],
 }