fix(polling): invisible quick poll dropdown

bigbluebutton-html5/imports/ui/components/presentation/component.jsx

@@ -840,6 +840,7 @@ class Presentation extends PureComponent {
                   height: svgDimensions.height < 0 ? 0 : svgDimensions.height,
                   textAlign: 'center',
                   display: !presentationIsOpen ? 'none' : 'block',
+                  zIndex: 1,
                 }}
                 id="presentationInnerWrapper"
               >

bigbluebutton-html5/imports/ui/components/presentation/styles.js

@@ -161,6 +161,7 @@ const PresentationToolbar = styled.div`
   order: 2;
   position: absolute;
   bottom: 0;
+  z-index: 2;
 `;
 
 const ToastSeparator = styled(ToastStyled.Separator)``;