rn: set default resolution to 360p (experiment)

android/app/src/main/java/org/jitsi/meet/MainActivity.java

             .setWelcomePageEnabled(true)
             .setServerURL(buildURL(defaultURL))
             .setFeatureFlag("call-integration.enabled", false)
+            .setFeatureFlag("resolution", 360)
             .setFeatureFlag("server-url-change.enabled", !configurationByRestrictions)
             .build();
         JitsiMeet.setDefaultConferenceOptions(defaultOptions);

ios/app/src/AppDelegate.m

     jitsiMeet.universalLinkDomains = @[@"meet.jit.si", @"alpha.jitsi.net", @"beta.meet.jit.si"];
 
     jitsiMeet.defaultConferenceOptions = [JitsiMeetConferenceOptions fromBuilder:^(JitsiMeetConferenceOptionsBuilder *builder) {
+        [builder setFeatureFlag:@"resolution" withValue:@(360)];
         builder.serverURL = [NSURL URLWithString:@"https://meet.jit.si"];
         builder.welcomePageEnabled = YES;