[Android] URBNG-355 & URBNG-356 

1. Completed subtasks URBNG-355 & URBNG-356:
Created flexible CustomView to representing either Login or Register fragment view, which will be facilitate all convenient methods to both fragments and hide whole implementation that must be done in both of them if view not exists.

2. Fixes from previous pull request.
3. Fixed bugs in layout that has been revealed during Demo with PdO