Android Crashfix: Problem caused by creating a GUI item on an async thread (non-gui).

thread #44, name = 'QtThread', stop reason = signal SIGSEGV: invalid address (fault address: 0x500000108)
 frame #0: 0x000000757d14436c libQt5Gui.so`QPainter::setBrushOrigin(this=<unavailable>, p=0x0000007569afaed8) at qpainter.cpp:2152:22
  ...
 frame #12: 0x000000757d61a2c4 libQt5Core.so`QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 76
 frame #13: 0x000000757d5bf4c8 libQt5Core.so`QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 556
 frame #14: 0x000000757cb89770 libQt5Widgets.so`QDialog::exec(this=0x0000007569afb990) at qdialog.cpp:602:26
 frame #15: 0x000000757abadd8c libkritawidgetutils.so`KoFileDialog::filename(this=<unavailable>) at KoFileDialog.cpp:250:26
 frame #16: 0x00000075797df994 libkritaui.so`KisImportExportManager::getUriForAdditionalFile(defaultUri=<Invalid>, parent=<unavailable>) at KisImportExportManager.cpp:291:19
 frame #17: 0x00000075797e275c libkritaui.so`KisImportExportManager::doExport(this=0x00000075729b82a0, location=<Invalid>, filter=<unavailable>, exportConfiguration=<unavailable>, alsoAsKra=true) at KisImportExportManager.cpp:684:31

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Test Plan

Save in a format like .png/.jpeg (where you also get an option to "Save as Kra"), check the "Also save your image as a Krita file" -- the saving should work just fine.

Formalities Checklist

• I confirmed this builds.
• I confirmed Krita ran and the relevant functions work.
• I tested the relevant unit tests and can confirm they are not broken. (If not possible, don't hesitate to ask for help!)
• I made sure my commits build individually and have good descriptions as per KDE guidelines.
• I made sure my code conforms to the standards set in the HACKING file.
• I can confirm the code is licensed and attributed appropriately, and that unattributed code is mine, as per KDE Licensing Policy.