如何在屏幕底部程序化设置android TabLayout？

<android.support.design.widget.TabLayout
    android:id="@+id/tabLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom"
    app:tabMode="fixed"
    app:tabGravity="fill" />

<android.support.v4.view.ViewPager
    android:id="@+id/viewPager"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

TabLayout tabLayout = findViewById(R.id.tabLayout);
ViewPager viewPager = findViewById(R.id.viewPager);

PagerAdapter pagerAdapter = new PagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(pagerAdapter);
tabLayout.setupWithViewPager(viewPager);

@Override
public int getCount() {
    return 3; // 假设有3个标签
}

@Override
public CharSequence getPageTitle(int position) {
    switch (position) {
        case 0:
            return "标签1";
        case 1:
            return "标签2";
        case 2:
            return "标签3";
        default:
            return null;
    }
}

@Override
public Fragment getItem(int position) {
    switch (position) {
        case 0:
            return new Fragment1();
        case 1:
            return new Fragment2();
        case 2:
            return new Fragment3();
        default:
            return null;
    }
}