title: "Expand more" with animation
body: <p>I am trying to do the same animation as Google :
  <a href="https://vid.me/9Wli" rel="nofollow">https://vid.me/9Wli</a></p>
  
  <p>A quick explanation about my app :</p>
  
  <p>At the top I have an AppBar, below it a LinearLayout including a button to expand more information and below this LinearLayout I have a RecyclerView.</p>
  
  <p>For the moment, when I click the "expand more" button, I just show some items with .setVisibility(View.VISIBLE), so I have no animation.</p>
  
  <p>Here is my actual XML code :</p>
  
  <pre><code>&lt;LinearLayout
      android:id="@+id/expandable_zone"
      android:layout_height="match_parent"
      android:layout_width="match_parent"
      android:orientation="vertical"
      android:visibility="gone"&gt;
  
      &lt;LinearLayout
          android:id="@+id/1"
          android:layout_height="wrap_content"
          android:layout_width="match_parent"
          android:orientation="vertical"&gt;
  
          &lt;TextView
              android:layout_height="wrap_content"
              android:layout_marginLeft="@dimen/activity_horizontal_margin"
              android:layout_width="wrap_content"
              android:text="@string/expandable_1"
              android:textColor="@color/secondaryTextDark"
              android:textSize="13dp" /&gt;
      &lt;/LinearLayout&gt;
  
      &lt;LinearLayout
          android:id="@+id/bottom_expandable_zone"
          android:layout_height="match_parent"
          android:layout_width="match_parent"
          android:orientation="vertical"&gt;
  
          &lt;TextView
              android:animateLayoutChanges="true"
              android:id="@+id/expand_more"
              android:layout_gravity="center_horizontal"
              android:layout_height="wrap_content"
              android:layout_marginBottom="11sp"
              android:layout_marginTop="11sp"
              android:layout_width="wrap_content"
              android:text="@string/expand_more"
              android:textColor="@color/secondaryTextDark" /&gt;
  
          &lt;ImageButton
              android:background="@drawable/circle_shape"
              android:id="@+id/expand_less"
              android:layout_gravity="center_horizontal"
              android:layout_height="wrap_content"
              android:layout_marginBottom="11sp"
              android:layout_marginTop="10sp"
              android:layout_width="wrap_content"
              android:src="@drawable/ic_check_grey600_24dp"
              android:visibility="gone" /&gt;
      &lt;/LinearLayout&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>Can anyone give me the best solution to do that ?</p>