Can't explain nor solve issue with fragment element in XML

Question

So far, the app has only one layout, activity_main.xml.

The application does runs but exits almost immediately on a usb-connected developer Android phone.

I tried debugging and troubleshooting the app, but the result was always the same: the app keeps quitting.

Finally, I tried to edit the only layout in the app, activity_main.xml. I started adding, removing, and swapping elements.

I found out that the app runs just fine when the fragment element is removed, and I don't know the explanation nor the solution to this issue.

Here's the activity_main.xml below. The fragment element I referred to has supportMap id property.

    <?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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">
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <FrameLayout
        android:id="@+id/driverStatusLayout"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/colorPrimary"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/totalOnlineDrivers"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_marginLeft="15dp"
            android:gravity="center"
            android:text="@string/total_online_drivers"
            android:textColor="@color/common_google_signin_btn_text_dark"
            android:textSize="22sp" />

        <android.support.v7.widget.SwitchCompat
            android:id="@+id/driverStatusSwitch"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="end"
            android:layout_marginRight="15dp"
            android:checked="false" />
    </FrameLayout>

    <fragment
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/supportMap"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/driverStatusLayout"
        tools:context="spartons.com.frisbeeGo.fragments.MapFragment" />

</RelativeLayout>
</android.support.constraint.ConstraintLayout>

Here's MainActivity.java:

package com.example.testbasna;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;

public class MainActivity extends AppCompatActivity {

    private GoogleMap googleMap;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }
}