@HNrrep5810 When pressing the button to select a skin, Minecraft opens Android's default file picker, "DocumentsUI". There is no option to select any other file picker.
This is still an issue on 1.19.73.02.
I am using a Google Pixel 6 Pro running Android 13 (March security update).
The skin I am trying to use is a 64x64 PNG, attached. I am able to upload and use it without trouble on Java Edition.
@HNrrep5810 When pressing the button to select a skin, Minecraft opens Android's default file picker, "DocumentsUI". There is no option to select any other file picker.