Don't allow file attachment from /data through GET_CONTENT.

A custom picker can be used to attach files to Compose activity. With
this change, we are disallowing files belonging to file:///data/... to
be attached from custom pickers, in order not to expose internal
application data.

If the Intent Uri is a "file" and the file is in
`Environment.getDataDirectory()`, then throw a
AttachmentFailureException
which is caught immediately and shows a toast to the user.

Details b/31494146#comment13
Fix b/32615212

Change-Id: I037888b01fef1cdf5053602cdf9194286d5648df
(cherry picked from commit eace8b43e8d1512a205554715ca840324bfbe35f)
1 file changed