Fix the stopping of the container in the ContainerSuite tests

Fix the stopping of the container in the ContainerSuite tests

[Bug/Feature]   The test took 10 seconds cause we issued a stop command
                before the container had a chance to start, effectively ignoring
                the stop command. The 10 seconds timeout triggered after which
                the container had been destroyed.
[Cause]         There is no proper way to know that the system inside the
                container has booted.
[Solution]      Add some small timeout to allow the container to start properly.
                Same thing is done in ContainerAdminSuite. There doesn't seem to
                be a better way for that.
[Verification]  Built, installed and run the tests.

Change-Id: I837588f93b335adab4ac5561b3a686af602e0c15
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>