Add interface and extend db to support storing slice uris

Bug: 126222433
Test: manual
Change-Id: Ie81e69477d297aa96a0daad02d56196c956271a3

src/com/android/settings/slices/Sliceable.java

@@ -22,6 +22,7 @@ import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.content.Context;
 import android.content.IntentFilter;
+import android.net.Uri;
 import android.widget.Toast;
 
 import com.android.settings.R;
@@ -54,6 +55,13 @@ public interface Sliceable {
         return false;
     }
 
+    /**
+     * Returns uri for this slice (if it's a slice).
+     */
+    default Uri getSliceUri() {
+        return null;
+    }
+
     /**
      * @return {@code true} if the setting update asynchronously.
      * <p>