Handle battery optimization exception

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

@@ -46,4 +46,5 @@
   <string name="hidden_app_name">Device Settings</string>
   <string name="hidden_alert">The app has been hidden. To open it again please dial 8722227 (TRACCAR).</string>
   <string name="error_msg_invalid_url">Please enter a valid http:// or https:// URL</string>
+  <string name="request_exception">To continuously collect location data please turn off battery optimization for the app.</string>
 </resources>