Migrate Dial pad tones preference

Bug: 364899400
Test: atest DialPadTonePreferenceTest
Flag: com.android.settings.flags.catalyst_sound_screen
Change-Id: I5939a4d41ad61337f38bd5d48a1cb74f14f1e397

src/com/android/settings/notification/SoundScreen.kt

@@ -40,7 +40,10 @@ class SoundScreen : PreferenceScreenCreator {
 
     override fun fragmentClass(): Class<out Fragment>? = SoundSettings::class.java
 
-    override fun getPreferenceHierarchy(context: Context) = preferenceHierarchy(this) {}
+    override fun getPreferenceHierarchy(context: Context) =
+        preferenceHierarchy(this) {
+            +DialPadTonePreference()
+        }
 
     companion object {
         const val KEY = "sound_screen"