Added a sleep scenario to platform_testing/.

Test: make PlatformCommonScenarioTests; install; instrument with "-e
class
android.platform.test.scenario.common.profile.CommonUserProfileTest
-e profile scenarios_sample_profile"
Bug: 119386011

Change-Id: I8e25a2cc0fb3cc03d6da2ca91f1d44b4cbe9a286