fix(ScreenObtainer): sync initialization
fix(ScreenObtainer): sync initialization

Will not crash, but delay requests if arrive, before the initialization
process is done (there is no way to tell that really).

adambowles/lib-jitsi-meet,jitsi/lib-jitsi-meet,adambowles/lib-jitsi-meet,nevermind-corp/ljm,jiyeyuran/lib-jitsi-meet,damencho/lib-jitsi-meet,jitsi/lib-jitsi-meet