[WAM] Initial start-up application (presumably resize) flicker

Close for MM 13.0.1

Okay, thanks a lot for these. Fyi, for the first one I can't really comment. But let me try all of these together to see how they work, and I'll ack that one as well.

Set of fixes:

• https://github.com/Igalia/chromium87/pull/5 (fixes first frame detection).

• https://github.com/Igalia/webosose-wam/pull/12 (fixes wrong resizes)

• https://gerrit.automotivelinux.org/gerrit/c/apps/html5-homescreen/+/27323 (tries to move background to be the last one to load).

We also have a problem with window dimensions passing, that is causing an unneeded resize.

Right now we have a workaround for showing immediately the first frame, as part of the first frame detection current implementation depends on old ozone wayland backend. We need to fix the implementation to also work with new ozone wayland backend.