I'm updating to RN 0.63 instead of the latest (0.66 at the time of this writing)
so we can update the navigation related libraries to their latest versions, and
then proceed with the larger leap towards the latest RN.
As a step toward merging jitsi-meet-react with jitsi-meet to share as
much source code as possible between mobile and Web, merge the part of
jitsi-meet-react's source tree which supports mobile inside the
jitsi-meet source tree and leave jitsi-meet-react's Web support in the
source code revision history but don't have it in master anymore because
it's different from jitsi-meet's Web support. In other words, the two
projects are mechanically merged at the file level and don't really
share source code between mobile and Web.