Remove mIsHalfWidth field from ContextualCard

mIsHalfWidth in ContextualCard is too generic to identify its
responsibility, it is used to hold the value of is_support_half from
database and used to decide the card width. Also, it limits the
relationship of CardType-to-Renderer not to be extended to one-to-many.

To deal with this, we replaced mIsHalfWidth with mViewType to implement
one-to-many relationship of CardType-to-Renderer, and removed all
related logic of mIsHalfWidth.

Bug: 121303357
Test: robotests, visual

Change-Id: I03e14392272194424f317d11bf9d0d794a6133f4