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* java/org/gnu/emacs/EmacsService.java (externalStorageAvailable)
(requestStorageAccess23, requestStorageAccess30)
(requestStorageAccess): New functions.

* lisp/startup.el (fancy-startup-tail, normal-splash-screen):
Call android-win functions for inserting the new storage
permission notice.

* lisp/term/android-win.el
(android-display-storage-permission-popup)
(android-after-splash-screen): New functions.

* src/android.c (android_init_emacs_service): Link to new Java
functions.
(android_external_storage_available_p)
(android_request_storage_access): New functions.

* src/android.h: Update prototypes.

* src/androidfns.c (Fandroid_external_storage_available_p)
(Fandroid_request_storage_access): New functions.
(syms_of_androidfns): Register new subrs.