feat(toolbox) added android screen share flag

Fixes issue #9435

react/features/base/flags/constants.js

@@ -92,6 +92,12 @@ export const IOS_RECORDING_ENABLED = 'ios.recording.enabled';
  */
 export const IOS_SCREENSHARING_ENABLED = 'ios.screensharing.enabled';
 
+/**
+ * Flag indicating if screen sharing should be enabled in android.
+ * Default: enabled (true).
+ */
+export const ANDROID_SCREENSHARING_ENABLED = 'android.screensharing.enabled';
+
 /**
  * Flag indicating if kickout is enabled.
  * Default: enabled (true).

react/features/toolbox/components/native/ScreenSharingAndroidButton.js

@@ -1,5 +1,9 @@
 // @flow
 
+import {
+    ANDROID_SCREENSHARING_ENABLED,
+    getFeatureFlag
+} from '../../../base/flags';
 import { translate } from '../../../base/i18n';
 import { IconShareDesktop } from '../../../base/icons';
 import { connect } from '../../../base/redux';
@@ -82,8 +86,11 @@ class ScreenSharingAndroidButton extends AbstractButton<Props, *> {
  * }}
  */
 function _mapStateToProps(state): Object {
+    const enabled = getFeatureFlag(state, ANDROID_SCREENSHARING_ENABLED, true);
+
     return {
-        _screensharing: isLocalVideoTrackDesktop(state)
+        _screensharing: isLocalVideoTrackDesktop(state),
+        visible: enabled
     };
 }