title: How to create content-provider across user profiles?
body: <p>For an embedded project building on the AOSP source, I have a big chunk of data in one (system) app that has to be accessible to other apps.  Yes, I know: the typical job for a content provider or service, but ... the same data (same single instance of that big chunk) has to be accessible to apps ON ALL USER PROFILES on the device!</p>
  
  <p>I already figured out that Android offers an android:singleUser="true" attribute for services, content-providers and receivers, but it has the annoying side-effect that it forces android:exported="false"!  Hence I assume that one solution could be to have in my Manifest one content provider using android:singleUser="true" and a second one which is android:exported="true" and have that second just query the first for the actual data that the other app might need, but ... that seems so ugly and in my case - where the app with content-providers and services already exists for single-user Android, it will require quite some changes.</p>
  
  <p>I also tried flagging my complete (system) application as android:persistent="true", but this resulted in problems accessing some parts of /data/data where the big chunk of data resides (which I need to debug further to get to the root cause).</p>
  
  <p>So, my question: is there any easy / advised way to create a content-provider (and same question for services and receivers in the same app) such that the app really acts as a singleton across multiple users (without being a System Service, since we don't want to affect system stability by running our stuff as part of the SystemServer)?</p>