Update preference screen title.

- Add missing title to preference screen xml so that they will be used to
set the activity title when the fragment is launched.
- Also updated some incorrect preference screen titles.
- Overrides getTitle() in preference fragments that do not use the
preference screen xml.

Bug: 64564191
Test: blaze-bin/screenshots/android/i18nscreenshots/i18nscreenshots
Change-Id: Id72d5ddf18f0962bc484de8bbd847a2e55d6371e

src/com/android/settings/applications/defaultapps/DefaultPhonePicker.java

@@ -23,6 +23,7 @@ import android.telecom.TelecomManager;
 import android.text.TextUtils;
 
 import com.android.internal.logging.nano.MetricsProto;
+import com.android.settings.R;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -43,6 +44,11 @@ public class DefaultPhonePicker extends DefaultAppPickerFragment {
                 (TelecomManager) context.getSystemService(Context.TELECOM_SERVICE));
     }
 
+    @Override
+    protected int getPreferenceScreenResId() {
+        return R.xml.default_phone_settings;
+    }
+
     @Override
     protected List<DefaultAppInfo> getCandidates() {
         final List<DefaultAppInfo> candidates = new ArrayList<>();