Add new hotseat bottom margin options

This changes how the hotseat height is calculated and by consequence how spaces are distributed in the workspace as well. This is the first of a series of changes that will improve and streamline workspace calculations.

Bug: 228998463
Fix: 234023782
Fix: 230191631
Fix: 232914299
Fix: 236238226
Test: manual, HSV and comparing to mocks
Change-Id: If021e8ba2c7c24c0bf9f27a1aa7aa946792ed04f
12 files changed