unpriv: Use "SIM <id>" instead of "Logical Slot <id>"

It does not make sense to refer to logical slot in an unprivileged
context.

app-unpriv/src/main/res/values/strings.xml

@@ -1,5 +1,6 @@
 <resources>
     <string name="app_name" translatable="false">EasyEUICC</string>
+    <string name="channel_name_format">SIM %d</string>
     <string name="compatibility_check">Compatibility Check</string>
 
     <!-- Compatibility Check Descriptions -->