Fix broken retaildemo tests

Bug: 38162695
Test: runtest frameworks-services -c
com.android.server.retaildemo.RetailDemoModeServiceTest &&
runtest frameworks-services -c
com.android.server.retaildemo.PreloadAppsInstallerTest

Change-Id: Iac60202414753b3e04e89cb29271cbd150a3acdd
2 files changed