title: Bottom Navigation Bar not shown in activity
body: <p>I have an activity with a title, a fragment with a recyclerview full of cards and a bottom navigaton bar.</p>
  
  <p>I cannot manage to show all 3 together without problems, the closest I have been is showing all 3, but with the bar taking space from the cards space.</p>
  
  <p>Right now this is the XML which I thought should be working:</p>
  
  <p></p>
  
  <pre><code>&lt;LinearLayout 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:orientation="vertical"
  tools:context=".habits.HabitsActivity"&gt;
  
      &lt;ImageView
          android:id="@+id/imageView"
          android:layout_width="313dp"
          android:layout_height="166dp"
          android:layout_gravity="center_horizontal"
          app:srcCompat="@drawable/goodreasons" /&gt;
  
  
  &lt;android.support.design.widget.CoordinatorLayout
      android:id="@+id/coordinatorLayout"
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
      &lt;FrameLayout
          android:id="@+id/contentFrame"
          android:layout_width="match_parent"
          android:layout_height="match_parent"&gt;&lt;/FrameLayout&gt;
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  
  
      &lt;FrameLayout
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_gravity="bottom"&gt;
  
  
  &lt;com.aurelhubert.ahbottomnavigation.AHBottomNavigation
      android:id="@+id/bottom_navigation"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_gravity="bottom" /&gt;
  
  &lt;/FrameLayout&gt;
  
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>But this gives this output:</p>
  
  <p><a href="https://i.stack.imgur.com/0xsQ8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0xsQ8.png" alt="enter image description here"></a></p>
  
  <p>This is the xml of the fragment, in case you think it is relevant too.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout 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:layout_gravity="center"
      android:orientation="vertical"
      android:padding="5dp"
  
  &gt;
  &lt;android.support.v7.widget.RecyclerView
      android:id="@+id/rv_list"
      android:layout_width="wrap_content"
      android:layout_height="match_parent"
      app:layout_constraintBottom_toBottomOf="parent"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintHorizontal_bias="0.0"
      app:layout_constraintStart_toStartOf="parent"
      app:layout_constraintTop_toTopOf="parent"
      app:layout_constraintVertical_bias="0.0"
      android:layout_gravity="center"
      /&gt;
  
  
  &lt;/LinearLayout&gt;
  </code></pre>