Add API to launch activities on secondary displays

displayId can be specified as a part of ActivityOptions.
We will look for a valid stack on the specified display, starting
from the topmost one. If no valid stack is found, new dynamic stack
can be created on external display.
Launch stack and display id can't be set at the same time, otherwise
exception will be thrown.

Test: ActivityManagerDisplayTests
Test: #testLaunchActivityOnSecondaryDisplay
Test: #testConsequentLaunchActivity
Test: #testConsequentLaunchActivityFromSecondaryDisplay
Test: #testLaunchActivityFromAppToSecondaryDisplay
Change-Id: I8a202bc076319e23948d81b99a2c68d7b733b5e4