overview / recents button disappears after task switch

**Describe the bug**
After task switching out of the calculator, I lose the overview/recents button from the softkeys. The overview button returns inside the settings menu, but disappears after exiting the settings menu. Killing the app brings the overview button back until the next time I switch away from it. This is the only app on my phone so affected. (Incidentally, this bug is also present in the stock Android calculator, and was present since I got this phone on Android 14, and has persisted through Androids 15 and 16. But maybe you can figure out what's happening!)

**To Reproduce**
Steps to reproduce the behavior:
1. Press the overview button (square) in the softkeys to bring up the app switcher
2. Select any app, or even select the calculator again
3. If you picked another app, switch back to the calculator
4. The overview button is now gone.

**Expected behavior**
The overview/recents button should always be present.

**Screenshots/videos**
Before switch:

During switch:

After switch. Note missing softkey on lower right!

**Smartphone (please complete the following information):**
- Device: Google Pixel 8a
- OS: Android 16 BP3A.251105.015
- App version: 3.2.0 (53)
- Language: English

**Additional context**
Add any other context about the problem here.

Start by reproducing the task-switching sequence on a Google Pixel 8a running Android 16, including returning from settings and killing the app. Compare the softkeys before and after switching; done means the overview/recents button remains present after returning to the calculator.

Written by the indexing model from the issue text.