[application] Fix black screen when switching from PVR Live TV channel to PVR Radio channel.

[ksooo]

This fixes #17556

When switching from a PVR Live TV to a PVR Radio channel, active window must be changed from WINDOW_FULLSCREEN_VIDEO to WINDOW_VISUALISATION. On stream change VideoPlayer fires a TMSG_SWITCHTOFULLSCREEN event which is handled by CApplication::OnApplicationMessage. The check for the active window there prevents switching the window, because when the event arrives the active window is still WINDOW_FULLSCREEN_VIDEO.

Same problem occurs when switching from Radio to Live TV since #17225, btw.

Removing the checks for the active window in CApplication::OnApplicationMessage fixes the issue and has no other negative side effects.

This issue is spacial to PVR, because VideoPalyer has special handling for PVR stream changes (fast channel switch).

Runtime tested on macOS and Android, latest Kodi master.

Hard to find a reviewer for this I guess (who is maintainer of CApplication?) , but maybe @phunkyfish can look at the change.

[phunkyfish]

How would we know this doesn’t impact anything outside of PVR?

Would it still work if only the visualisation check was omitted?

[ksooo]

How would we know this doesn’t impact anything outside of PVR?

I did extensive runtime tests with all kind of media. If I missed something, our general Kodi testing strategy will come to play - let our (alpha-)users test it in the nightlies.

... and @MilhouseVH could you add this PR to your builds, please?

[ksooo]

Would it still work if only the visualisation check was omitted?

No. At least vis and fullscreen video checks must go. Otherwise either TV->Radio or Radio->TV will not work.

[MilhouseVH]

... and @MilhouseVH could you add this PR to your builds, please?

Will do - should be in #0329

[ksooo]

No negative feedback from Milhouse build testers. Going to merge this now.