title: Access another app's data with sharedUserId
body: <p>I have an app that already is on the market, let's call it "old app". I would like to create a "new app" that shares the data with the old one app I decided to do it using a SharedID.</p>
  
  <p>I changed the manifest of the NEW app adding the following line:</p>
  
  <pre><code>android:sharedUserId="com.myname.myoldapp"
  </code></pre>
  
  <p>Where com.myname.myoldapp is the name of the old app package. But it does not work.</p>
  
  <p>How can I access with the new app to the old app data?
  Changing the userId of the old app to match the shareduserid of the new one, is obviously not an option, because the old app is already online and all users that update it would lose their personal data.</p>
  
  <p>PS: the certificates are the same.</p>
  
  <p>Thank you,.</p>