[remoting android] Add padding around the no-hosts text.

remoting/android/java/res/layout/main.xml

 <?xml version="1.0" encoding="utf-8"?>
 
 <!-- Copyright 2014 The Chromium Authors. All rights reserved.
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file.
 -->
 
 <android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/drawer_layout"
     android:layout_width="match_parent"
@@ skipping 14 matching lines @@
             android:layout_width="match_parent">
             <ListView
                 android:id="@+id/hostList_chooser"
                 android:layout_height="match_parent"
                 android:layout_width="match_parent"/>
             <LinearLayout
                 android:id="@+id/hostList_empty"
                 android:gravity="center"
                 android:layout_height="match_parent"
                 android:layout_width="match_parent"
+                android:padding="16dp"
                 android:orientation="vertical"
                 android:visibility="gone">
                 <ImageView
                     android:layout_height="wrap_content"
                     android:layout_width="wrap_content"
                     android:src="@drawable/empty_host_list"
                     android:padding="16dp"
                     android:contentDescription="@null"/>
                 <TextView
                     android:gravity="center"
@@ skipping 29 matching lines @@
     <LinearLayout
         android:id="@+id/navigation_drawer"
         android:layout_width="300dp"
         android:layout_height="match_parent"
         android:orientation="vertical"
         android:layout_gravity="start"
         android:background="@android:color/background_light"
         android:fitsSystemWindows="true">
     </LinearLayout>
 </android.support.v4.widget.DrawerLayout>