title: layout_gravity="bottom" doesn't work
body: <p>Hello stackoverflow community!
  I'm newbie both in programming and on this site, but let's get to the point.
  I wrote an app:</p>
  
  <pre><code>    &lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout 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"
      android:layout_weight="1"
      android:orientation="vertical"&gt;
  
  &lt;LinearLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:baselineAligned="false"
      android:orientation="horizontal"
      android:layout_marginTop="10dp"&gt;
  
      &lt;LinearLayout
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_weight="2"
          android:orientation="vertical"
          tools:context="com.example.android.courtcounter.MainActivity"
          android:padding="24dp"&gt;
  
          &lt;TextView
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:gravity="center_horizontal"
              android:padding="4dp"
              android:text="Team A"
              android:textSize="14sp"
              android:fontFamily="sans-serif-medium"/&gt;
  
          &lt;TextView
              android:id="@+id/team_a_score"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:gravity="center_horizontal"
              android:padding="4dp"
              android:text="0"
              android:textSize="56sp"
              android:textColor="#000000"
              android:fontFamily="sans-serif-light" /&gt;
  
          &lt;Button
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_margin="4dp"
              android:onClick="plus3a"
              android:text="+3 Points" /&gt;
  
          &lt;Button
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_margin="4dp"
              android:onClick="plus2a"
              android:text="+2 Points" /&gt;
  
          &lt;Button
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_margin="4dp"
              android:onClick="plus1a"
              android:text="Free throw" /&gt;
      &lt;/LinearLayout&gt;
  
      &lt;View
          android:layout_width="1dp"
          android:background="@android:color/darker_gray"
          android:layout_height="match_parent"&gt;
  
      &lt;/View&gt;
  
      &lt;LinearLayout
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_weight="2"
          android:orientation="vertical"
          tools:context="com.example.android.courtcounter.MainActivity"
          android:padding="24dp"&gt;
  
          &lt;TextView
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:gravity="center_horizontal"
              android:padding="4dp"
              android:text="Team B"
              android:textSize="14sp"
              android:fontFamily="sans-serif-medium"/&gt;
  
          &lt;TextView
              android:id="@+id/team_b_score"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:gravity="center_horizontal"
              android:padding="4dp"
              android:text="0"
              android:textSize="56sp"
              android:textColor="#000000"
              android:fontFamily="sans-serif-light"/&gt;
  
          &lt;Button
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_margin="4dp"
              android:onClick="plus3b"
              android:text="+3 Points" /&gt;
  
          &lt;Button
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_margin="4dp"
              android:onClick="plus2b"
              android:text="+2 Points" /&gt;
  
          &lt;Button
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_margin="4dp"
              android:onClick="plus1b"
              android:text="Free throw" /&gt;
      &lt;/LinearLayout&gt;
  
  &lt;/LinearLayout&gt;
  
  &lt;LinearLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical"&gt;
  
      &lt;Button
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_gravity="bottom|center_horizontal"
          android:onClick="scoreReset"
          android:text="reset" /&gt;
      &lt;/LinearLayout&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>I have a problem with positioning a button at the end.
  I want it to be at the bottom of a screen and centered horizontally.
  I know I could use relative layout but I decided to check if I can do this using linear layout. And seems that I can't... "bottom" attribute is being ignored.</p>