title: how to use tabContentStart to start content from middle of device screen
body: <p>I am using <strong>TabLayout</strong> and <strong>ViewPager</strong></p>
  
  <pre><code>&lt;android.support.v4.view.ViewPager
          android:id="@+id/view_pager_social_profiles"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          app:layout_behavior="@string/appbar_scrolling_view_behavior"&gt;&lt;/android.support.v4.view.ViewPager&gt;
  
  &lt;android.support.design.widget.TabLayout
          android:id="@+id/tab_layout_social_profiles"
          android:layout_width="match_parent"
          android:layout_height="112dp"
          app:tabContentStart="72dp"
          app:tabGravity="center"
          app:tabIndicatorHeight="0dp"
          app:tabMode="scrollable"&gt;&lt;/android.support.design.widget.TabLayout&gt;
  </code></pre>
  
  <p>I want to start tab content from the middle of screen so if there is only one tab it will be aligned exactly center of screen (horizontally) and also selected tab will be always in center.</p>