Clean up: delete unused methods

Test: rebuild
Change-Id: I144ebbdaf137ee091af949a9e38f68d02941f705
diff --git a/src/com/android/settings/SettingsPreferenceFragment.java b/src/com/android/settings/SettingsPreferenceFragment.java
index 70b96c4..af88c2d 100644
--- a/src/com/android/settings/SettingsPreferenceFragment.java
+++ b/src/com/android/settings/SettingsPreferenceFragment.java
@@ -540,10 +540,6 @@
         private DialogInterface.OnCancelListener mOnCancelListener;
         private DialogInterface.OnDismissListener mOnDismissListener;
 
-        public SettingsDialogFragment() {
-            /* do nothing */
-        }
-
         public SettingsDialogFragment(DialogCreatable fragment, int dialogId) {
             super(fragment, dialogId);
             if (!(fragment instanceof Fragment)) {
diff --git a/src/com/android/settings/connecteddevice/usb/UsbDetailsFragment.java b/src/com/android/settings/connecteddevice/usb/UsbDetailsFragment.java
index b548477..1217a34 100644
--- a/src/com/android/settings/connecteddevice/usb/UsbDetailsFragment.java
+++ b/src/com/android/settings/connecteddevice/usb/UsbDetailsFragment.java
@@ -17,7 +17,6 @@
 package com.android.settings.connecteddevice.usb;
 
 import android.content.Context;
-import android.os.Bundle;
 import android.provider.SearchIndexableResource;
 
 import androidx.annotation.VisibleForTesting;
@@ -69,15 +68,6 @@
     }
 
     @Override
-    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
-        super.onCreatePreferences(savedInstanceState, rootKey);
-    }
-
-    public boolean isConnected() {
-        return mUsbReceiver.isConnected();
-    }
-
-    @Override
     protected List<AbstractPreferenceController> createPreferenceControllers(Context context) {
         mUsbBackend = new UsbBackend(context);
         mControllers = createControllerList(context, mUsbBackend, this);