title: React native margin: 'auto' working on web but not on device
body: <p>I am building an application which uses react native on expo dev. I am trying to add a button in the top left corner which is adjacent to some text o the right hand side, I have used <code>marginRight: 'auto'</code> for this and it does display as expected on the web version but on the app version on Android it appears centered as if the margin styling is ignored, any solutions?</p>
  <pre><code>&lt;View style={styles.header}&gt;
    
    &lt;View style={styles.headerTop}&gt;
      &lt;Text style={styles.headerText}&gt;Question {currentQuestion+1}/{questions.length}&lt;/Text&gt;
      &lt;TouchableOpacity 
        onPress={() =&gt; navigation.navigate(&quot;Home&quot;)}
        style= {styles.exitButton}
        &gt;
        &lt;Text style={styles.buttonText}&gt;Exit&lt;/Text&gt;
        &lt;/TouchableOpacity&gt;
        &lt;/View&gt;
      &lt;Text style={styles.timer}&gt;{timer}&lt;/Text&gt;
    &lt;/View&gt;
  
      header: {
      flexGrow: 0,
      padding: 8,
    },
    headerTop: {
      flexDirection: 'row-reverse',
    },
    headerText: {
      fontSize: 24,
      textAlign: 'right',
    },
  exitButton: {
      padding: 12,
      paddingHorizontal: 12,
      backgroundColor: '#1BA7F9',
      borderRadius: 12,
      marginRight: 'auto',
    },
    buttonText: {
      fontSize: 20,
    }
  </code></pre>