Viewer renders flickering images

[saran-t]

See microsoft/MoCapAct#8

[saran-t]

Running dm_control==1.0.6 with mujoco==2.2.1 resolves the viewer rendering issue, however this isn't supported since parts of dm_control==1.0.6 use API calls that depend on mujoco==2.2.2.

[saran-t]

Bisecting shows that the issue was introduced in google-deepmind/mujoco#425 or 42527bc

Investigating a fix