Missing handling of NULL values for the mapping function

[dankr3]

Actual behaviour

The sitemap function is not mapping the value NULL to the corresponding field.
The following entry is currently in my sitemap:
Selection item=OG_SZ_Echo_Command label="Activity" mappings=[NULL="- SELECT -", "switch TV on"="TV on", "switch TV off"="TV off"]
The item is bind to the Amazon Echo and write only. Therefore it's always NULL.
The app didn't show - as expected - the "- SELECT -" value. Instead, it shows nothing ("")

Expected behaviour

The sitemap that is executed in the browser is working correctly.
In the e.g. the Chrome Browser it shows the correct mapped value: "- SELECT -" instead of "".

Steps to reproduce

1. Create an item with the value NULL.
2. Create a "Selection" entry in the sitemap that is mapped the NULL value (as described under "Actual behaviour).
3. Show in Android and in Browser - see the difference.

Environment data

Client

• Android version: 14
• Device model: Galaxy S23
• App version : 3.17.2
• Build flavor : Full
• Device language: DE

Server

• Server version: 4.3.3
• Reverse Proxy: None
• Authentication method : None