feat(screenshare): allow auto-pin remote only

interface_config.js

 
     // Browsers, in addition to those which do not fully support WebRTC, that
     // are not supported and should show the unsupported browser page.
-    UNSUPPORTED_BROWSERS: []
+    UNSUPPORTED_BROWSERS: [],
+
+    /**
+     * A UX mode where the last screen share participant is automatically
+     * pinned. Valid values are the string "remote-only" so remote participants
+     * get pinned but not local, otherwise any truthy value for all participants,
+     * and any falsy value to disable the feature.
+     *
+     * Note: this mode is experimental and subject to breakage.
+     */
+    AUTO_PIN_LATEST_SCREEN_SHARE: 'remote-only'
 
     /**
      * How many columns the tile view can expand to. The respected range is
      */
     // ANDROID_APP_PACKAGE: 'org.jitsi.meet',
 
-    /**
-     * A UX mode where the last screen share participant is automatically
-     * pinned. Note: this mode is experimental and subject to breakage.
-     */
-    // AUTO_PIN_LATEST_SCREEN_SHARE: false,
-
     /**
      * Override the behavior of some notifications to remain displayed until
      * explicitly dismissed through a user action. The value is how long, in

react/features/video-layout/subscriber.js

             = store.getState()['features/video-layout'].screenShares || [];
         const knownSharingParticipantIds = tracks.reduce((acc, track) => {
             if (track.mediaType === 'video' && track.videoType === 'desktop') {
-                acc.push(track.participantId);
+                const skipTrack
+                    = interfaceConfig.AUTO_PIN_LATEST_SCREEN_SHARE === 'remote-only'
+                        && track.local;
+
+                if (!skipTrack) {
+                    acc.push(track.participantId);
+                }
             }
 
             return acc;