title: Android O Preview : ConnectivityManager removed methods are not backward compatible
body: <p>Precondition and build config: I am trying to build my app with AndroidStudio 2.4 review 5 by setting below build config paramters for Android O perview device,
      compileSdkVersion 'android-O'
      buildToolsVersion '25.0.0'
      compileOptions.encoding = 'ISO-8859-1'
      minSdkVersion 16
      targetSdkVersion 'O'
      // Enabling multidex support.
      multiDexEnabled true </p>
  
  <p>Issue Description: My app uses these below deprecated methods of ConnectivityManager class for devices with older version of android.
  -<code>ConnectivityManager.startUsingNetworkFeature()</code> 
  - <code>ConnectivityManager.stopUsingNetworkFeature()</code>
  - <code>ConnectivityManager.requestRouteToHost()</code></p>
  
  <p>When I try to build my app which has these above api, it is giving compile time error as follows,</p>
  
  <p>Error:(626, 48) error: cannot find symbol method startUsingNetworkFeature(int,String)
  Error:(7393, 27) error: cannot find symbol method stopUsingNetworkFeature(int,String)
  Error:(69, 36) error: cannot find symbol method requestRouteToHost(int,int)</p>
  
  <p>Ideally these api should not give compile time error for backward compatibity purpose.
  Please let me know how to resolve these compile time errors.</p>
  
  <p>I can't remove these methods from code as they are required for devices with older android version(less than Android L version)</p>