Bugfix for "non-primary" external storage provider folder uris.

[quantum-byte]

Implemented a fix to support non "primary" external storage document provider uris like "home:" for the "documents" folder.

Fixed Issue / How to reproduce:

1. Create a folder "Documents" under "storage/emulated/0" ( under Android 9 or 10 - for example on the android emulator)
2. Try to define this folder as a Backup folder
3. Crash

java.lang.NullPointerException: path must not be null
	at de.lolhens.resticui.util.DirectoryChooser$Companion$DefaultDirectoryChooser.register$lambda$0(DirectoryChooser.kt:48)
	at de.lolhens.resticui.util.DirectoryChooser$Companion$DefaultDirectoryChooser.$r8$lambda$jK8O1H1CKL7PB9Zkehlu4Bw5Rh0(Unknown Source:0)
	at de.lolhens.resticui.util.DirectoryChooser$Companion$DefaultDirectoryChooser$$ExternalSyntheticLambda0.onActivityResult(Unknown Source:6)
	at androidx.activity.result.ActivityResultRegistry$1.onStateChanged(ActivityResultRegistry.java:149)
	at androidx.lifecycle.LifecycleRegistry$ObserverWithState.dispatchEvent(LifecycleRegistry.java:360)
	at androidx.lifecycle.LifecycleRegistry.forwardPass(LifecycleRegistry.java:271)
	at androidx.lifecycle.LifecycleRegistry.sync(LifecycleRegistry.java:313)
	at androidx.lifecycle.LifecycleRegistry.moveToState(LifecycleRegistry.java:151)
	at androidx.lifecycle.LifecycleRegistry.handleLifecycleEvent(LifecycleRegistry.java:134)
	at androidx.fragment.app.Fragment.performStart(Fragment.java:3167)
	at androidx.fragment.app.FragmentStateManager.start(FragmentStateManager.java:588)
	at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:279)
	at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:113)
	at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1433)
	at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:2977)
	at androidx.fragment.app.FragmentManager.dispatchStart(FragmentManager.java:2902)
	at androidx.fragment.app.Fragment.performStart(Fragment.java:3171)
	at androidx.fragment.app.FragmentStateManager.start(FragmentStateManager.java:588)
	at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:279)
	at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:113)
	at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1433)
	at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:2977)
	at androidx.fragment.app.FragmentManager.dispatchStart(FragmentManager.java:2902)
	at androidx.fragment.app.FragmentController.dispatchStart(FragmentController.java:274)
	at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:359)
	at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:251)
	at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1433)
	at android.app.Activity.performStart(Activity.java:7924)
	at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3332)
	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$H.handleMessage(ActivityThread.java:2044)
	at android.os.Handler.dispatchMessage(Handler.java:107)
	at android.os.Looper.loop(Looper.java:224)
	at android.app.ActivityThread.main(ActivityThread.java:7560)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)

The content uri looks like the this: content:https://com.android.externalstorage.documents/tree/home%3A/document/home%3A and causes the issue.

[quantum-byte]

Regarding 2066bb4.

Ah my bad. I wanted to exclude that. git commit -a strikes again 😅

[lhns]

Just released your fix with v0.4.4