title: How to implement a back arrow in fragment
body: <p>I have a nav drawer which in its first fragment i have a news page where the user clicks a button to see the whole news, and at that moment it enters another fragment.</p>
  
  <p>I want to know how I implement an arrow to return to the previous fragment instead of the icon that opens the Navigation Drawer.</p>
  
  <p>I've never worked with this before, I have no idea.</p>
  
  <p>This is my Toolbar in MainActivity</p>
  
  <pre><code>appBarLayout = (AppBarLayout) findViewById(R.id.appBarLayout);
  
  toolbar = (Toolbar) findViewById(R.id.toolbar);
  //toolbar title
  toolbar.setTitle(null);
  setSupportActionBar(toolbar);
  getSupportActionBar().setDisplayShowTitleEnabled(false);
  // Toolbar logo
  logoToolbar = (ImageView) findViewById(R.id.logoToolbar);
  logoToolbar.setImageResource(R.drawable.newstoolbar);
  </code></pre>
  
  <p>When the user click in "Read More" in the MainFragment</p>
  
  <pre><code>newsMore.get(0).setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  FragmentTransaction ft = getFragmentManager().beginTransaction();
                  ft.setCustomAnimations(R.anim.fade_in, R.anim.fade_out);
  
                  newsFrag1 newsFragment1 = new newsFrag1();
                  ft.replace(R.id.fragment_container, newsFragment1);
                  ft.commit();
              }
  });
  </code></pre>
  
  <p>And then it goes to newsFrag1, which I want to have the back arrow</p>
  
  <p>My Toolbar XML</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.design.widget.CoordinatorLayout 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:fitsSystemWindows="true"
      tools:context="studio.com.archeagemanager.MainActivity"&gt;
  
      &lt;android.support.design.widget.AppBarLayout
          android:id="@+id/appBarLayout"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:theme="@style/AppTheme.AppBarOverlay"
          app:elevation="0dp"&gt;
  
  
          &lt;android.support.v7.widget.Toolbar
              android:id="@+id/toolbar"
              android:layout_width="match_parent"
              android:layout_height="?attr/actionBarSize"
              android:layout_weight="1"
              android:background="?attr/colorPrimary"
              android:gravity="center_vertical"
              android:minHeight="56dp"
              android:weightSum="1"
              app:popupTheme="@style/AppTheme.PopupOverlay"&gt;
  
              &lt;ImageView
                  android:id="@+id/logoToolbar"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_gravity="center" /&gt;
  
          &lt;/android.support.v7.widget.Toolbar&gt;
  
      &lt;/android.support.design.widget.AppBarLayout&gt;
  
      &lt;FrameLayout
          android:id="@+id/fragment_container"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_marginTop="56dp"&gt;
      &lt;/FrameLayout&gt;
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>