App crashes when long-pressing a symbol to reveal more characters

[MoralCode]

Describe the bug
After having edited the symbols layout (via the "customize symbols layout" menu, I was able to consistently reproduce and then fix an app crash.

To Reproduce
Steps to reproduce the behavior:

1. open the openboard app
2. click advanced
3. under experimental, click "customize symbols layout" (or the other one, it should be the same)
4. add a space to the end of any key (remember which one it is, i used the line where the _ underscore character was)
5. go to another app with a text input
6. long press the key with the modified symbol map (the underscore)

Expected behavior
keyboard crashes consistently when steps 5 and 6 repeated until step 4 is un-done

Smartphone (please complete the following information):

• Device: Google Pixel 6
• OS: Android 14, LineageOS 21

Additional context
undoing this process fixed the issue. redoing it to a different key caused it to come back

Suggested solution (maybe its not viable): Trim whitespace from the end of each line of the key customization file upon saving (assuming non-newline whitespace characters are not allowed in this file)