Don't override bounds to include insets for floating activities

Insets have been decoupled from app bounds from V+. To keep the legacy
behaviour, we override the app bounds to include insets for apps
targeting older sdks. However, floating windows do not include insets
and thus the app bounds in this case should not be adjusted to include
them.

Flag: EXEMPT bugfix
Test: Manual && atest WmTests:SizeCompatTests
Fixes: 348202594
Change-Id: I2d472e4d92f5be95b448e9fed4a2cd7d2f45517e