title: 'paddingLeft' and 'paddingStart' are necessary in layout.xml, but errors in custom_style.xml
body: <p>Im current working on a Udacity Android project, and I have noticed something that I can't seem to find an answer on. Using custom style resources to remove the style aspect from the layout.xml files is something I'm trying to learn and use correctly. </p>
  
  <p>However, I have ran into an issue.</p>
  
  <p>As you know with <code>padding</code> it is recommended to use <code>paddingStart</code> and <code>paddingEnd</code> simultaneously with <code>paddingLeft</code> and <code>paddingRight</code> and this is for a few reasons:</p>
  
  <ol>
  <li>Right-to-Left orientation support</li>
  <li>Lower-API level support (I believe that <code>start</code> and <code>end</code> began at API 17)</li>
  </ol>
  
  <p>In layouts, the Android Studio IDE recommends putting both methods (I assume with Right and Left being the fallback in case you are using an older version of Android). However, when porting the exact options to a style.xml, I am given an error about the lack of API 17 support available to use <code>start/end</code>(my project is API 15). How is that the <code>left</code> and <code>right</code> options aren't allowing <code>end</code> and <code>start</code> to exist in the style resource?</p>
  
  <p><strong>Example:</strong></p>
  
  <p>Here is a snippet from a working <strong>layout.xml</strong> before applying style resources:</p>
  
  <pre><code>&lt;LinearLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:paddingLeft="15dp"
      android:paddingRight="15dp"
      android:paddingStart="15dp"
      android:paddingEnd="15dp"  /&gt;
  </code></pre>
  
  <p>And here is a style sheet (with an error) that takes the styles from this <strong>layout.xml</strong> file and adds them to a style resource called <strong>custom_styles.xml</strong>... </p>
  
  <pre><code>&lt;style name="CustomStyle"&gt;
      &lt;item name="android:layout_width"&gt;match_parent&lt;/item&gt;
      &lt;item name="android:layout_height"&gt;match_parent&lt;/item&gt;
      &lt;item name="android:paddingLeft"&gt;15dp&lt;/item&gt;
      &lt;item name="android:paddingRight"&gt;15dp&lt;/item&gt;
      &lt;item name="android:paddingStart"&gt;15dp&lt;/item&gt;
      &lt;item name="android:paddingEnd"&gt;15dp&lt;/item&gt;
  </code></pre>
  
  <p>The error is at <code>paddingStart</code> and <code>paddingEnd</code> and simply states that the API level of the project is to low to support that. This error does not occur in the <strong>layout.xml</strong> snippet I've added above.</p>
  
  <p>What is the difference between style resource and layout resource in this particular case?</p>