Como fazer para a ListView aparecer por baixo do menu de navegação e ainda permanecer clicável?

Quero fazer o list view aparecer abaixo do menu e não fique em cima do menu de navegação, porém quando altero a ordem das views o list view deixa de ser clicável e uma parte fica coberta pelo menu.

activity_main.xml :

<?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"
    android:fitsSystemWindows="true">

    <android.support.v4.widget.DrawerLayout
        android:id="@+id/drawerLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        tools:layout_editor_absoluteX="56dp"
        tools:layout_editor_absoluteY="44dp"
        tools:openDrawer="start">

        <include layout="@layout/toolbar" />

        <android.support.design.widget.NavigationView
            android:id="@+id/navView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="start"
            app:headerLayout="@layout/nav_header"
            app:menu="@menu/menu_nav" >

        </android.support.design.widget.NavigationView>

    </android.support.v4.widget.DrawerLayout>

    <Button
        android:id="@+id/main_cadastrar"
        android:layout_width="56dp"
        android:layout_height="56dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginBottom="16dp"
        android:background="@drawable/fundo_botao"
        android:elevation="6dp"
        android:stateListAnimator="@null"
        android:text="+"
        android:textColor="#ffff"
        android:textSize="28sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <ListView
        android:id="@+id/lista"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

    </ListView>

</android.support.constraint.ConstraintLayout>

toolbar.xml :

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />

</LinearLayout>

Perdão pela desorganização.