PossibleMaximumWindowMetrics reports physical display insets for each

DisplayInfo (current and non-current display)

Changes behaviour from dumbly applying the insets of the current
DisplayInfo to all other DisplayInfo, to reading the insets of each
DisplayInfo into WindowMetrics. Additionally, applies the appropriate
rotation to the insets of each DisplayInfo, so the WindowMetrics
contain the correctly-rotated insets.

Bug: 201546646
Test: Manual
Change-Id: I5756a768b7544939d55d5759f838b27278ca1da6