Improve shadow quality for bigger views

Bigger views has harder edges with shapes that're not very well aligned.
This cl adds radius that's dependent on the size of views.

Bug: 123334471
Test: Unit tests
Change-Id: Icb62d02cafbf29c5919013ef273248245b53c83d
(cherry picked from commit 019c5ea9effef700263aec3fa4bd8d241193bfdf)