Add group to system user on Android
<p>I am developing an application along with a custom Android ROM that requires me to access a certain folder in the Android file system. The application has System privileges and the user 
System prints following when executing </p>

<pre><code>id
</code></pre>

<p>Output:</p>

<pre><code>uid=1000(system) gid=1000(system) groups=1001(radio),1002(bluetooth),1003(graphics),1004(input),1005(audio),1006(camera),1007(log),1008(compass),1009(mount),1010(wifi),1018(usb)
</code></pre>

<p>The folder that I need to access is created by another user (an Android application on the Libraries layer) and is limited to a group which I am not part of.</p>

<p>So my questions are:
Where in the Android source code would it be suitable to add the user System to the existing group? (Or how is it done with the other groups that System is part of)</p>