fix(screenshot-capture): Move the flag for enabling/disabling the feature to config.js

This will let us enable/disable the feature based on environment/deployment

conference.js

         } else {
             promise = promise.then(() => this.useVideoStream(null));
         }
-
-        APP.store.dispatch(toggleScreenshotCaptureEffect(false));
+        if (config.enableScreenshotCapture) {
+            APP.store.dispatch(toggleScreenshotCaptureEffect(false));
+        }
 
         return promise.then(
             () => {
             .then(stream => this.useVideoStream(stream))
             .then(() => {
                 this.videoSwitchInProgress = false;
-                APP.store.dispatch(toggleScreenshotCaptureEffect(true));
+                if (config.enableScreenshotCapture) {
+                    APP.store.dispatch(toggleScreenshotCaptureEffect(true));
+                }
                 sendAnalytics(createScreenSharingEvent('started'));
                 logger.log('Screen sharing started');
             })

interface_config.js

      */
     AUTO_PIN_LATEST_SCREEN_SHARE: 'remote-only',
 
-    /**
-     * If we should capture periodic screenshots of the content sharing.
-     */
-    ENABLE_SCREENSHOT_CAPTURE: false,
-
     /**
      * If true, presence status: busy, calling, connected etc. is not displayed.
      */

react/features/base/config/configWhitelist.js

     'enableLayerSuspension',
     'enableLipSync',
     'enableRemb',
+    'enableScreenshotCapture',
     'enableTalkWhileMuted',
     'enableNoAudioDetection',
     'enableNoisyMicDetection',

react/features/stream-effects/screenshot-capture/ScreenshotCaptureEffect.js

      * @returns {boolean} - Returns true if this effect can run on the specified track, false otherwise.
      */
     isEnabled(jitsiLocalTrack: Object) {
-        return (
-            interfaceConfig.ENABLE_SCREENSHOT_CAPTURE
-            && jitsiLocalTrack.isVideoTrack()
-            && jitsiLocalTrack.videoType === 'desktop'
-        );
+        return jitsiLocalTrack.isVideoTrack() && jitsiLocalTrack.videoType === 'desktop';
     }
 
     /**