Added new tile views for densified explore sites pages.

This involves the following changes:

1) Adding new dimensions in the XML to meet the spec for the explore sites
page.

2) Adding new tile views using new dimensions.

3) setting the tile view to use in CategoryCardViewHolderFactory.

4) Adjustments to the code for RoundedIconGenerator and
RoundedBitmapDrawable so that the icon size and radius are
programmatically adjusted.

5) Removal of an extra resize in ExploreSitesTileView which cause icons
to scale too many times creating resizing artifacts for both dense and
regular views. The RoundedBitmapDrawable already handles density based
resizing.

These changes form the bulk of the explore sites densification view
changes. What is left will be tweaks to padding on the category cards
and changes in tile quantity rendering logic.

Moved new dense feature params to a custom CondensedVariation, to be
wrapped under the condensed feature param in ExploreSitesVariation.
Added new supporting enums and utilities to allow access to condensed
variation from ExploreSitesBridge.

Bug: 977713
Change-Id: I795372339ea6350da6767aa613c55aeb2383bbaa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1681955
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Reviewed-by: Cathy Li <chili@chromium.org>
Commit-Queue: Angel Alvarez <angelii@google.com>
Cr-Commit-Position: refs/heads/master@{#675783}