Remove usages of ActionBarActivity.

ActionBarActivity has been deprecated for 2+ years and has been
extending AppCompatActivity for all that time. These changes
should be no-ops.

Bug: 35253513
Test: None
Change-Id: I392de8c0d64fb4ed2210215c72539b02fa5bb734

samples/BindingDemo/app/src/main/java/com/android/example/bindingdemo/MainActivity.java

diff --git a/samples/BindingDemo/app/src/main/java/com/android/example/bindingdemo/MainActivity.java b/samples/BindingDemo/app/src/main/java/com/android/example/bindingdemo/MainActivity.java
index bcdcdba..00bd05d 100644
--- a/samples/BindingDemo/app/src/main/java/com/android/example/bindingdemo/MainActivity.java
+++ b/samples/BindingDemo/app/src/main/java/com/android/example/bindingdemo/MainActivity.java
@@ -4,7 +4,7 @@
 import android.databinding.DataBindingUtil;
 import android.databinding.Observable;
 import android.databinding.Observable.OnPropertyChangedCallback;
-import android.support.v7.app.ActionBarActivity;
+import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
@@ -24,7 +24,7 @@
 import java.util.List;
 
 import  com.android.example.bindingdemo.BR;
-public class MainActivity extends ActionBarActivity implements Observable {
+public class MainActivity extends AppCompatActivity implements Observable {
     @Bindable
     UserAdapter tkAdapter;
     @Bindable