MM-51912 - fix not able to scroll in the LHS (#22806)

webapp/channels/src/components/sidebar/sidebar_list/__snapshots__/sidebar_list.test.tsx.snap

@@ -54,7 +54,6 @@ exports[`SidebarList should match snapshot 1`] = `
       renderView={[Function]}
       style={
         Object {
-          "overflow": "initial",
           "position": "absolute",
         }
       }

webapp/channels/src/components/sidebar/sidebar_list/sidebar_list.tsx

@@ -69,7 +69,7 @@ export function renderThumbVertical(props: any) {
     );
 }
 
-const scrollbarStyles: CSSProperties = {position: 'absolute', overflow: 'initial'};
+const scrollbarStyles: CSSProperties = {position: 'absolute'};
 
 type Props = {
     currentTeam: Team;

webapp/channels/src/sass/layout/_sidebar-left.scss

@@ -578,7 +578,6 @@ $sidebarOpacityAnimationDuration: 0.15s;
     @media screen and (min-width: 768px) {
         .SidebarNavContainer {
             .scrollbar--view {
-                overflow: initial !important;
                 max-width: 240px;
             }
         }
@@ -754,7 +753,7 @@ $sidebarOpacityAnimationDuration: 0.15s;
     }
 
     .AddChannelsCtaDropdown .dropdown-menu {
-        min-width: 232px !important;
+        min-width: 210px !important;
         margin-left: 20px;
     }