Add ConnectivityManager.getNetworkWatchlistConfigHash()

Apps can use this API to get network watchlist config hash for auditing.

Bug: 63908748
Test: Able to compile
Change-Id: I5ce9e6bb6dad88139c0a102da58be0dd7c284b7a
diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 11d338d..166342d 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -3763,4 +3763,20 @@
             throw e.rethrowFromSystemServer();
         }
     }
+
+    /**
+     * The network watchlist is a list of domains and IP addresses that are associated with
+     * potentially harmful apps. This method returns the hash of the watchlist currently
+     * used by the system.
+     *
+     * @return Hash of network watchlist config file. Null if config does not exist.
+     */
+    public byte[] getNetworkWatchlistConfigHash() {
+        try {
+            return mService.getNetworkWatchlistConfigHash();
+        } catch (RemoteException e) {
+            Log.e(TAG, "Unable to get watchlist config hash");
+            throw e.rethrowFromSystemServer();
+        }
+    }
 }