[Catalyst] Update PreferenceLifecycleContext.notifyPreferenceChange

Change the signature from metadata to preference key, so that the API
could be used to notify other preferences on the same screen.

NO_IFTTT=Catalyst only

Bug: 332201912
Flag: com.android.settings.flags.catalyst
Test: atest
Change-Id: Ibdf5f9004471d5491a0be1e84365cbe9f136c373

src/com/android/settings/display/darkmode/DarkModeScreen.kt

@@ -112,7 +112,7 @@ class DarkModeScreen :
         val broadcastReceiver =
             object : BroadcastReceiver() {
                 override fun onReceive(receiverContext: Context, intent: Intent) {
-                    context.notifyPreferenceChange(this@DarkModeScreen)
+                    context.notifyPreferenceChange(KEY)
                 }
             }
         context.registerReceiver(
@@ -121,7 +121,7 @@ class DarkModeScreen :
         )
 
         val darkModeObserver = DarkModeObserver(context)
-        darkModeObserver.subscribe { context.notifyPreferenceChange(this@DarkModeScreen) }
+        darkModeObserver.subscribe { context.notifyPreferenceChange(KEY) }
 
         fragmentStates[context] = FragmentState(broadcastReceiver, darkModeObserver)
     }