Fix unmount up button

import android.widget.TextView;

import com.android.internal.logging.MetricsProto.MetricsEvent;

import com.android.settings.InstrumentedFragment;

import com.android.settings.R;

import com.android.settings.SettingsPreferenceFragment;

import com.android.settings.deviceinfo.StorageSettings.UnmountTask;

public class PrivateVolumeUnmount extends InstrumentedFragment {

public class PrivateVolumeUnmount extends SettingsPreferenceFragment {

    private VolumeInfo mVolume;

    private DiskInfo mDisk;