Docs: Clarified certain restrictions to whitelisted apps

</p>

<p>

  An app that is whitelisted can use the network and hold

  <a href="{@docRoot}reference/android/os/PowerManager.html#PARTIAL_WAKE_LOCK">

  partial wake locks</a> during Doze and

  App Standby. However, <strong>other restrictions still apply</strong> to the

  whitelisted app, just as they do to other apps. For example, the whitelisted

  app’s jobs and syncs are deferred, and its regular {@link android.app.AlarmManager} alarms do not

  fire. An app can check whether it is currently on the exemption whitelist by

  calling {@link

  An app that is whitelisted can use the network and hold <a href=

  "{@docRoot}reference/android/os/PowerManager.html#PARTIAL_WAKE_LOCK">partial

  wake locks</a> during Doze and App Standby. However, <strong>other

  restrictions still apply</strong> to the whitelisted app, just as they do to

  other apps. For example, the whitelisted app’s jobs and syncs are deferred

  (on API level 23 and below), and its regular {@link android.app.AlarmManager}

  alarms do not fire. An app can check whether it is currently on the exemption

  whitelist by calling {@link

  android.os.PowerManager#isIgnoringBatteryOptimizations(java.lang.String)

  isIgnoringBatteryOptimizations()}.

  </li>

</p>

<p>

  Users can manually configure the whitelist in <strong>Settings &gt; Battery

  &gt; Battery Optimization.</strong> Alternatively, the system provides

  ways for apps to ask users to whitelist them.

</p>

<ul>