Currently, due to some services/graphics issues onShow callback is not being
called and therefore tests are not executed. For screen-less devices graphics
stack should not be required and therefore moving test execution to onInit

This patch allows ACTS tests output to be shown on the logs

Signed-off-by: Robert Drab <robert.drab@huawei.com>
Signed-off-by: Francesco Pham <francesco.pham@huawei.com>