Add adb command to toggle side stage outline border

Make the outline boarder of the side stage default off. Add an adb
command to toggle on/off the boarder.

$adb shell dumpsys activity service SystemUIService WMShell
setSideStateOutline <true/false>

Bug: 189839391
Test: verified the adb command could toggle on/off side stage outline
border.

Change-Id: I4c09b072b384badd206f0e81eca6daa033ac8565