Ensure that the Hotseat respects the margins of the QSB.

Before this change they were ignored by onMeasure(), so that the QSB
couldn't rely on margins for its positioning.

Bug: 217477426
Test: manual
Change-Id: Ifecd3d40ea584273b7857d19b25a90dbafe1c656
(cherry picked from commit 410c75a4)