Draft: Update HMI test cases to use gstreamer

HMI is supported in 32 bit architectures, however, Flathub does not support them any more. Also, running flatpak applications can be very demanding for low end/old boards. These two issues make impossible to properly test HMI in 32 architectures.

As an improvement switch to use gstreamer to run the tests which is supported and less demanding.

infrastructure/apertis-issues#752

Signed-off-by: Walter Lozano walter.lozano@collabora.com