(touch-mode-md 2.1/n) Add md touch mode support in WMS

The md touch mode logic can be described as following:
* If config_perDisplayFocusEnabled is set to true, then
  WMS#setInTouchMode will only switch the touch mode for the target
  display;
* Otherwise (in case config_perDisplayFocusEnabled is set to false)
  WMS#setInTouchMode will switch the touch mode for all existing
  displays (disregarding from the displayId parameter).

Major changes in this CL:
* Update/add touch mode methods in IWindowManager.aidl with displayId
  param;
* Remove touch mode related methods in IWindowSession.aidl since touch
  mode is a DisplayContent's field now;
* Update WMS#setInTouchMode (and related code) with the md touch mode
  logic described in this CL.

Bug: 198499018
Test: atest FrameworksCoreTests WindowManagerServiceTests
Test: atest CarServiceUnitTest CtsInputTestCases
Test: manual (car multi-display emulator)

Change-Id: I8b93a0b50e279b6cdc2524e279d337aea378b9a2