To see messges in notification drop-down list there is need use instead:
ApplicationFolderIntegrationConfig config = new
ApplicationFolderIntegrationConfig(true, true,
ApplicationDescriptor.currentApplicationDescriptor());
folder_ = amfr.registerFolder(MyFolderId , "My Folder", collection_, config);
instead:
folder_ = amfr.registerFolder(MyFolderId , "My Folder", collection_, true);