DownloadManager: process intents from external apps

That's required in Pico4Ultra to receive intents from the Android's
DownloadManager. Without that, things like downloading environments
don't work because we don't get notified when the download is
finished.

Fixes #1740

app/src/common/shared/com/igalia/wolvic/downloads/DownloadsManager.java

@@ -70,8 +70,8 @@ private void removeDownloadOnDiskIO(long id) {
 
     public void init() {
         IntentFilter filter = new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-            mContext.registerReceiver(mDownloadReceiver, filter, null, mMainHandler, Context.RECEIVER_NOT_EXPORTED);
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            mContext.registerReceiver(mDownloadReceiver, filter, null, mMainHandler, Context.RECEIVER_EXPORTED);
         } else {
             mContext.registerReceiver(mDownloadReceiver, filter, null, mMainHandler);
         }