support opening USB-OTG on android-29+

Here's another gem: they added this nice new API in android-24 and told
everyone this was THE WAY. Then they made it a no-op in android-29
https://developer.android.com/reference/android/os/storage/StorageVolume#createAccessIntent(java.lang.String)

app/src/full/java/org/fdroid/fdroid/nearby/TreeUriScannerIntentService.java

@@ -74,6 +74,11 @@ public class TreeUriScannerIntentService extends IntentService {
     public static final String TAG = "TreeUriScannerIntentSer";
 
     private static final String ACTION_SCAN_TREE_URI = "org.fdroid.fdroid.nearby.action.SCAN_TREE_URI";
+    /**
+     * @see <a href="https://android.googlesource.com/platform/frameworks/base/+/android-10.0.0_r38/core/java/android/provider/DocumentsContract.java#238">DocumentsContract.EXTERNAL_STORAGE_PROVIDER_AUTHORITY</a>
+     * @see <a href="https://android.googlesource.com/platform/frameworks/base/+/android-10.0.0_r38/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java#70">ExternalStorageProvider.AUTHORITY</a>
+     */
+    public static final String EXTERNAL_STORAGE_PROVIDER_AUTHORITY = "com.android.externalstorage.documents";
 
     public TreeUriScannerIntentService() {
         super("TreeUriScannerIntentService");

app/src/full/java/org/fdroid/fdroid/nearby/UsbDeviceAttachedReceiver.java

@@ -19,25 +19,19 @@
 
 package org.fdroid.fdroid.nearby;
 
-import android.app.Activity;
 import android.content.BroadcastReceiver;
-import android.content.ComponentName;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
-import android.content.IntentFilter;
 import android.content.UriPermission;
 import android.database.ContentObserver;
 import android.hardware.usb.UsbManager;
 import android.net.Uri;
 import android.os.Build;
-import android.os.Bundle;
 import android.os.Handler;
-import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import android.text.TextUtils;
 import android.util.Log;
-import org.fdroid.fdroid.views.main.MainActivity;
+import androidx.annotation.RequiresApi;
 import org.fdroid.fdroid.views.main.NearbyViewBinder;
 
 

app/src/full/java/org/fdroid/fdroid/views/main/NearbyViewBinder.java

@@ -13,6 +13,7 @@ import android.os.Build;
 import android.os.Environment;
 import android.os.storage.StorageManager;
 import android.os.storage.StorageVolume;
+import android.provider.DocumentsContract;
 import android.text.TextUtils;
 import android.util.Log;
 import android.view.View;
@@ -21,11 +22,9 @@ import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
-
 import androidx.annotation.RequiresApi;
 import androidx.core.app.ActivityCompat;
 import androidx.core.content.ContextCompat;
-
 import org.fdroid.fdroid.R;
 import org.fdroid.fdroid.Utils;
 import org.fdroid.fdroid.nearby.SDCardScannerService;
@@ -61,6 +60,8 @@ import java.util.List;
  *
  * @see TreeUriScannerIntentService
  * @see org.fdroid.fdroid.nearby.SDCardScannerService
+ * <p>
+ * TODO use {@link StorageManager#registerStorageVolumeCallback(Executor, StorageManager.StorageVolumeCallback)}
  */
 public class NearbyViewBinder {
     public static final String TAG = "NearbyViewBinder";
@@ -165,11 +166,26 @@ public class NearbyViewBinder {
         for (final StorageVolume storageVolume : storageManager.getStorageVolumes()) {
             if (storageVolume.isRemovable() && !storageVolume.isPrimary()) {
                 Log.i(TAG, "StorageVolume: " + storageVolume);
-                final Intent intent = storageVolume.createAccessIntent(null);
+                Intent tmpIntent = null;
-                if (intent == null) {
+                if (Build.VERSION.SDK_INT < 29) {
+                    tmpIntent = storageVolume.createAccessIntent(null);
+                } else {
+                    tmpIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
+                    tmpIntent.putExtra(DocumentsContract.EXTRA_INITIAL_URI,
+                            Uri.parse("content://"
+                                    + TreeUriScannerIntentService.EXTERNAL_STORAGE_PROVIDER_AUTHORITY
+                                    + "/tree/"
+                                    + storageVolume.getUuid()
+                                    + "%3A/document/"
+                                    + storageVolume.getUuid()
+                                    + "%3A"));
+                }
+                if (tmpIntent == null) {
                     Utils.debugLog(TAG, "Got null Storage Volume access Intent");
                     return;
                 }
+                final Intent intent = tmpIntent;
+
                 storageVolumeText.setVisibility(View.VISIBLE);
 
                 String text = storageVolume.getDescription(context);