Allow home app being instrumented while starting home from PhoneWindowManager

The Launcher tests about home key will go througth PhoneWindowManager
and call to RootActivityContainer#startHomeOnDisplay().
The original startHomeOnDisplay() calls canStartHomeOnDisplay() with
allowInstrumenting=false and causes the tests fail.

This patch allow home app being instrumented while staring home from
PhoneWindowManager.

Bug: 129073085
Test: adb shell am instrument -w -r -e debug false -e log false -e class com.android.quickstep.TaplTestsQuickstep#testOverview com.google.android.apps.nexuslauncher.tests/androidx.test.runner.AndroidJUnitRunner
Change-Id: If6e2c748bed034866b3d4c3e40554c34373a333c