This test spawns several services backed by /system/bin/yes executable,
and then stops them either while SIGTERM or SIGKILL.
Ideally we want to unit test more of reboot logic, but that requires a
bigger refactoring.
Test: atest CtsInitTestCases
Bug: 170315126
Bug: 174335499
Change-Id: Ife48b1636c6ca2d0aac73f4eb6f4737343a88e7a
