Renamed primaryUserOnly to systemUserOnly

In the split mode, broadcast receivers and activities marked as
systemUserOnly will be running as system. This is a non-functional change for
non-split system user mode.

Bug: 22958572
Change-Id: I0f7d4f4a81275bc326bf630a776c695e8b5291a6
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index fefd5a7..7304872 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2804,7 +2804,7 @@
         </activity>
 
         <receiver android:name="com.android.server.BootReceiver"
-                android:primaryUserOnly="true">
+                android:systemUserOnly="true">
             <intent-filter android:priority="1000">
                 <action android:name="android.intent.action.BOOT_COMPLETED" />
             </intent-filter>