Add feature flag for REGISTER_NSD_OFFLOAD_ENGINE permission

Bug: 304478692
Test: TH
Change-Id: I7e190b7d14e5818fb68af1753bf149366d01e61d
diff --git a/core/api/system-current.txt b/core/api/system-current.txt
index 3d01011..95dc07f 100644
--- a/core/api/system-current.txt
+++ b/core/api/system-current.txt
@@ -298,7 +298,7 @@
     field public static final String RECOVER_KEYSTORE = "android.permission.RECOVER_KEYSTORE";
     field public static final String REGISTER_CALL_PROVIDER = "android.permission.REGISTER_CALL_PROVIDER";
     field public static final String REGISTER_CONNECTION_MANAGER = "android.permission.REGISTER_CONNECTION_MANAGER";
-    field public static final String REGISTER_NSD_OFFLOAD_ENGINE = "android.permission.REGISTER_NSD_OFFLOAD_ENGINE";
+    field @FlaggedApi("com.android.net.flags.register_nsd_offload_engine") public static final String REGISTER_NSD_OFFLOAD_ENGINE = "android.permission.REGISTER_NSD_OFFLOAD_ENGINE";
     field public static final String REGISTER_SIM_SUBSCRIPTION = "android.permission.REGISTER_SIM_SUBSCRIPTION";
     field public static final String REGISTER_STATS_PULL_ATOM = "android.permission.REGISTER_STATS_PULL_ATOM";
     field public static final String REMOTE_DISPLAY_PROVIDER = "android.permission.REMOTE_DISPLAY_PROVIDER";
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 0e753e5..f7b6a7b 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2278,6 +2278,7 @@
     <!-- Allows system apps to call methods to register itself as a mDNS offload engine.
         <p>Not for use by third-party or privileged applications.
         @SystemApi
+        @FlaggedApi("com.android.net.flags.register_nsd_offload_engine")
         @hide This should only be used by system apps.
     -->
     <permission android:name="android.permission.REGISTER_NSD_OFFLOAD_ENGINE"