FRAGMENT CON 2 BOTTONI
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.fragment.app.FragmentContainerView
android:id = "@+id/fragmentContainer"
android:layout_width="match_parent"
android:layout_height="600dp" />
<Button
android:id = "@+id/fragmentBtn"
android:layout_width="150dp"
android:layout_height="60dp"
android:backgroundTint="@color/black"
android:layout_alignParentBottom="true"
android:layout_marginBottom="50dp"
