Remove debug boolean from StackScrollAlgorithm

The debug boolean is only checked from log and logView which are
only used locally for debugging. Having to flip debug to true is
an unnecessary extra step before writing debug logs. Remove this
boolean and prefix log and logView with "debug" for clarity.

Fixes: 330376903
Test: SystemUITests
Change-Id: Id8de2d444806fefd04c74b90d220fc29224bb6c2