Untitled Stories on first publish on WPAndroid

[mzorz]

When publishing new Stories, all of them are uploaded as "Untitled", even when a title has been specified in the Pre-publishing bottom sheet.

Steps to reproduce:

1. Tap on WPAndroid's My Site FAB icon, choose new Story
2. select one ore more media items from the media picker
3. once the Story composer loads up with the selected items as slides, tap on the check mark on the top-right corner of the screen
4. the bottom sheet appears, enter a title for your post
5. tap on PUBLISH
6. after publishing, see the Posts list on the Published tab
7. observe the newly created Post is named Untitled.