Version: 6233 v4.21.0 crashes when opening Settings, Import and Export, Export all

[ChrisD70]

Describe the bug
Selecting Export all or Track export directory in Settings/Import and Export crashes OpenTracks

To Reproduce

1. Go to Settings
2. Click on Import and Export
3. Click on Export all
4. Error:

Exception in thread "main": java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
	at androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor(AppCompatDelegateImpl.java:902)
	at androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor(AppCompatDelegateImpl.java:865)
	at androidx.appcompat.app.AppCompatDelegateImpl.onPostCreate(AppCompatDelegateImpl.java:561)
	at androidx.appcompat.app.AppCompatActivity.onPostCreate(AppCompatActivity.java:149)
	at android.app.Instrumentation.callActivityOnPostCreate(Instrumentation.java:1491)
	at android.app.ActivityThread.handleStartActivity(ActivityThread.java:4246)
	at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
	at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
	at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2584)
	at android.os.Handler.dispatchMessage(Handler.java:106)
	at android.os.Looper.loopOnce(Looper.java:226)
	at android.os.Looper.loop(Looper.java:313)
	at android.app.ActivityThread.main(ActivityThread.java:8810)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:604)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1067)

### App information
* ID: de.dennisguse.opentracks.playstore
* Version: 6233 v4.21.0

### Device information
* Brand: samsung
* Device: gta4xlwifi
* Model: SM-P610
* Id: TP1A.220624.014
* Product: gta4xlwifieea

### Firmware
* SDK: 33
* Release: 13
* Incremental: P610XXS7FYD1

The last working version is commit edac784b, the changes in c34e9bd7 cause the crash.

Tested on different devices with Android 11, 12 and 13.

[dennisguse]

🤔

[dennisguse]

Fixed in 6f65808

Released as v4.21.1: https://github.com/OpenTracksApp/OpenTracks/releases/tag/v4.21.1

PS/ The whole theming in Androidx is way too complicated.
I will add this to my "things that should be refactored, because it didn't age will"-list.