Updated the sample

 - Removed editing, because it is not ready for the sdk yet
 - Added sync of a default group
 - Demo for "View group"
 - Demo for "View Stream Item" and "View Stream Item Photo"
 - Demo for invite flow (at least show a dialog)
 - Hardcoded demo username and password into the dialog (it is in the
   source anyway)

Bug:5383087

Change-Id: I4cf18eb8e90df872f832ecd74f22d68de6099e60
27 files changed