title: Make two apps communicate with each other using same signature
body: <p>I have App A that has defined a permission with protection level as signature. This app starts a service that belongs to App B. It calls startService(intent) repeatedly (only the intent class name is defined to call the service). </p>
  
  <p>I need to ensure that only App B receives the onStartCommand() and not other rogue apps (if someone tries to reverse engineer and create a service with same name etc). Do i define the same permission even in App B's manifest? </p>
  
  <pre><code>&lt;permission
      android:name="my.android.permissions.MY_PERM"
      android:protectionLevel="signature" /&gt;
  
  &lt;uses-permission android:name="my.android.permissions.MY_PERM" /&gt;
  </code></pre>
  
  <p>This permission is already defined in App A's manifest. </p>