Added Corner Layout

[cvgarciarea]

GCI Task: https://codein.withgoogle.com/dashboard/task-instances/5119622560874496/

To know how the icons are arranged:
https://s14.postimg.org/zcr55soep/corner_layout.png

[quozl]

Tested an earlier draft.

Reviewed. Comments;

• setup does not offset the owner icon by allocation.y, result may be collision,
• the activity icon is not excluded from child allocation area, result may be collision,
• CornerLayout.setup is mostly duplicated from ViewLayout.setup, we would prefer calling method instead of copy and paste, as that would reduce the number of code lines to be maintained,
• might use self._grid for collision detection instead of pixel coordinates,
• might use RandomLayout as parent class, in similar fashion to how previous layouts inherit from RingLayout.

[rhl-bthr]

@cristian99garcia, will you be updating the patch or may I do the same, Thanks

[ghost]

Hi ! Is there anything that still needs to be done?Both the links on the parent comment are dead.

[rhl-bthr]

@mk1299, see review comments for what needs to be done in the patch

[quozl]

Yeah, please everybody in future don't use links that expire.