Fix for 2202408: Replace Never Timeout with 30 minutes

Maximum timeout is now 30 minutes. Never Timeout will cause
burn-in problems with OLED and a bit with LCD as well.
diff --git a/res/values/arrays.xml b/res/values/arrays.xml
index 5191d83..6d8ca32 100644
--- a/res/values/arrays.xml
+++ b/res/values/arrays.xml
@@ -79,12 +79,11 @@
         <item>1 minute</item>
         <item>2 minutes</item>
         <item>10 minutes</item>
-        <!-- Choosing this means the screen will only turn off after the user manually does so.  There will be no inactivity check. -->
-        <item>Never timeout</item>
+        <item>30 minutes</item>
     </string-array>
 
     <!-- Do not translate. -->
-    <string-array name="screen_timeout_values">
+    <string-array name="screen_timeout_values" translatable="false">
         <!-- Do not translate. -->
         <item>15000</item>
         <!-- Do not translate. -->
@@ -96,7 +95,7 @@
         <!-- Do not translate. -->
         <item>600000</item>
         <!-- Do not translate. -->
-        <item>-1</item>
+        <item>1800000</item>
     </string-array>
 
     <!-- TTS settings -->