Auto frontlight plugin: Newer Oasis models are also supported (#9202)

On a Kindle Oasis 2 and 3 the plugin would be disabled due to not
checking for "KindleOasis2" and "KindleOasis3" respectively.

plugins/autofrontlight.koplugin/main.lua

@@ -1,7 +1,10 @@
 local Device = require("device")
 
 if not Device:isKindle() or
-   (Device.model ~= "KindleVoyage" and Device.model ~= "KindleOasis") then
+   (Device.model ~= "KindleVoyage" and
+    Device.model ~= "KindleOasis" and
+    Device.model ~= "KindleOasis2" and
+    Device.model ~= "KindleOasis3") then
     return { disabled = true, }
 end