use androidx alertdialog instead of default one

dependencies {

    implementation 'androidx.legacy:legacy-support-v4:1.0.0'

    implementation "androidx.appcompat:appcompat:1.1.0-alpha04"

    implementation 'com.google.code.gson:gson:2.8.5'

package com.nextcloud.android.sso.ui;

import android.app.AlertDialog;

import android.app.NotificationChannel;

import android.app.NotificationManager;

import android.content.Context;

import android.content.DialogInterface;

import androidx.appcompat.app.AlertDialog;

import androidx.core.app.NotificationCompat;

import android.text.SpannableString;

import android.text.method.LinkMovementMethod;