feat(toolbar) add flag for autohiding while chat open (#11104)

config.js

     //     timeout: 4000,
     //     // Moved from interfaceConfig.TOOLBAR_ALWAYS_VISIBLE
     //     // Whether toolbar should be always visible or should hide after x miliseconds.
-    //     alwaysVisible: false
+    //     alwaysVisible: false,
+    //     // Indicates whether the toolbar should still autohide when chat is open
+    //     autoHideWhileChatIsOpen: false
     // },
 
     // Toolbar buttons which have their click/tap event exposed through the API on

react/features/toolbox/actions.web.js

 export function hideToolbox(force: boolean = false): Function {
     return (dispatch: Dispatch<any>, getState: Function) => {
         const state = getState();
-        const { toolbarConfig: { alwaysVisible } } = state['features/base/config'];
+        const { toolbarConfig: { alwaysVisible, autoHideWhileChatIsOpen } } = state['features/base/config'];
         const { hovered } = state['features/toolbox'];
         const toolbarTimeout = getToolbarTimeout(state);
 
         if (!force
                 && (hovered
                     || state['features/invite'].calleeInfoVisible
-                    || state['features/chat'].isOpen
+                    || (state['features/chat'].isOpen && !autoHideWhileChatIsOpen)
                     || document.querySelector(focusSelector))) {
             dispatch(
                 setToolboxTimeout(