Merge "Make the executor pool size as 1"

import static com.android.documentsui.base.SharedMinimal.DEBUG;

import androidx.annotation.IntDef;

import android.app.Notification;

import android.app.NotificationChannel;

import android.app.NotificationManager;

import android.os.IBinder;

import android.os.PowerManager;

import android.os.UserManager;

import androidx.annotation.VisibleForTesting;

import android.util.Log;

import androidx.annotation.IntDef;

import androidx.annotation.VisibleForTesting;

import com.android.documentsui.R;

import com.android.documentsui.base.Features;

    static final String NOTIFICATION_CHANNEL_ID = "channel_id";

    private static final int POOL_SIZE = 2;  // "pool size", not *max* "pool size".

    // This is a temporary solution, we will gray out the UI when a transaction is in progress to

    // not enable users to make a transaction.

    private static final int POOL_SIZE = 1;  // Allow only 1 executor operation

    @VisibleForTesting static final int NOTIFICATION_ID_PROGRESS = 1;

    private static final int NOTIFICATION_ID_FAILURE = 2;