Add secondary launcher for multi-display

This app is modified from development/samples/MultiDisplay, then rename
package to com.android.car.multidisplay, and package name becomes
MultiDisplaySecondaryHomeTestLauncher.

This apk should be only included for multi-display target,
as done in device/panasonic/hawk/hawk_md.mk

Bug: 131312580

Test: lunch hawk_md-userdebug

Change-Id: I9dc8d1e0e71e270030135339b3e619f5d87a9ade
34 files changed