Files on Android are read-only for app-files-path

[xprojects-de]

see also ionic-team/capacitor-plugins#2268

Is your feature request related to a problem? Please describe.
Files from the APP-Files directory are opened read-only and are not editable even if the files-path permission is set in the FileProviderXML

...     
<files-path name="app_files" path="." />
...

Describe the solution you'd like
The solution would be to set also the Intent.FLAG_GRANT_WRITE_URI_PERMISSION flag in the intent.

Describe alternatives you've considered
Maybe with another input flag "writeAccess: true"!?

Additional context
We have an ICONIC app for our music as a music reader and would like to have access to the sheet music (PDF), which is stored in the app-files directory, for editing.