This streamlines the upload from files, e.g. from email attachments.
Closes #9215.
The approach via the listener mFileDisplayNameTransformer was chosen
because this allows a potential extension to multiple files (with multiple
input fields). Alternatively, ReceiveExternalFilesActivity#uploadFile()
could've been used, which requires the storage to a temporary file
first.
nextFocusForward and nextFocusDown are both needed to support navigation
with the Tab key as well as the Enter key
Signed-off-by: Philipp Hasper <vcs@hasper.info>

This streamlines the renaming and speeds up the process.
Signed-off-by: Philipp Hasper <vcs@hasper.info>

When running the screenshot tests, the following error was raised:
com.owncloud.android.ui.activity.ReceiveExternalFilesActivityIT > openMultiAccount[uiComparison(AVD) - 9] FAILED
java.lang.AssertionError: Can't create multiple screenshots with the same name: com.owncloud.android.ui.activity.ReceiveExternalFilesActivityIT_open
at com.facebook.testing.screenshot.internal.AlbumImpl.addRecord
This happened because openMultiAccount() simply calls the open() test which
"hardcodes" the screenshot name
Signed-off-by: Philipp Hasper <vcs@hasper.info>

The UI only allows to proceed with the upload, if the permissions are
given accordingly, so the test setup needs access to the corresponding
permission keys.
Instead of only making one of the keys available, all were made public.
Because why should these magic strings be private after all? This only
invites duplication and hinders maintenance.
Signed-off-by: Philipp Hasper <vcs@hasper.info>

The automated test only tests this partially, because the only invalid
name was an emtpy name. All other characters which are typically unsuitable
for a filename, like the directory separator '/' are not properly rejected
during the test run, because the FileNameValidator is based on the user
capabilities, which are null because this is a sever-less test.
Signed-off-by: Philipp Hasper <vcs@hasper.info>

Signed-off-by: Philipp Hasper <vcs@hasper.info>

To reduce duplication, the file and folders are setup in a @before method,
but this also affects the existing screenshot tests.
Signed-off-by: Philipp Hasper <vcs@hasper.info>

Working around the limitation of returns as well as the condition
complexity was attempted but made the code just less readable.
Ignoring these two specific findings is more appropriate here.
Signed-off-by: Philipp Hasper <vcs@hasper.info>

Signed-off-by: Philipp Hasper <vcs@hasper.info>