Move webrtc/{tools => rtc_tools}

webrtc/rtc_tools/network_tester/androidapp/res/layout/activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/activity_main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:paddingStart="@dimen/activity_horizontal_margin"
     android:paddingEnd="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     android:paddingBottom="@dimen/activity_vertical_margin"
     tools:context="com.google.media.networktester.MainActivity">
     <Button
       android:text="@string/start_test"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_alignParentTop="true"
       android:layout_alignParentStart="true"
       android:id="@+id/start_button"/>
     <Button
       android:text="@string/interrupt_test"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_alignParentTop="true"
       android:layout_toEndOf="@+id/start_button"
       android:id="@+id/stop_button"/>
 
 </RelativeLayout>