title: Add back button to Toolbar for all Fragments other than Home Fragment which opens Navigation Drawer
body: <p>When my application is opened Home screen is shown first.On Home screen I have <code>NavigationDrawer</code> which get opened after pressing <code>HamburgerIcon</code>.Later i go to different fragments.When I am in Other fragments other than Home <code>Activity</code> I need to show back button on <code>Toolbar</code> to come to previous fragment.But its every time showing Hamburger icon.How to do this ?<br>
  This is code for setting <code>Toolbar</code> in XML </p>
  
  <pre><code>&lt;android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:id="@+id/drawerLayout"
      tools:context="biz.fyra.myApp.ActivityTwo"&gt;
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:orientation="vertical"&gt;
          &lt;android.support.v7.widget.Toolbar
              android:id="@+id/toolbar"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:background="#ccc"
              android:minHeight="?attr/actionBarSize"&gt;
              &lt;ImageView
                  android:id="@+id/tooImage"
                  android:src="@drawable/latest"
                  android:layout_width="match_parent"
                  android:layout_gravity="center_horizontal"
                  android:layout_height="40dp" /&gt;
          &lt;/android.support.v7.widget.Toolbar&gt;
          &lt;FrameLayout
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:id="@+id/frame"&gt;
          &lt;/FrameLayout&gt;
      &lt;/LinearLayout&gt;
      &lt;android.support.design.widget.NavigationView
          android:layout_width="300dp"
          android:layout_height="match_parent"
          android:layout_gravity="start"
          app:headerLayout="@layout/nav_header"
          android:id="@+id/navigationView"
          app:menu="@menu/actionmenu"
          android:background="@android:color/white"&gt;
      &lt;/android.support.design.widget.NavigationView&gt;
  &lt;/android.support.v4.widget.DrawerLayout&gt;  
  </code></pre>
  
  <p>How to achieve this ?</p>