fix #1929 by using flex instead of grid to lay out the tabs view (#1930)

less/documentDB.less

@@ -2352,8 +2352,8 @@ a:link {
 
 .tabsManagerContainer {
   height: 100%;
-  display: grid;
-  grid-template-rows: 36px 36px 1fr;
+  display: flex;
+  flex-direction: column;
   min-width: 0; // This prevents it to grow past the parent's width if its content is too wide
 }
 
@@ -2610,9 +2610,8 @@ a:link {
 }
 
 .tabPanesContainer {
-  grid-row: span 2; // Fill the remaining space
   display: flex;
-  height: 100%;
+  flex-grow: 1;
   overflow: hidden;
 }
 

src/Explorer/Tabs/Tabs.tsx

@@ -57,7 +57,8 @@ export const Tabs = ({ explorer }: TabsProps): JSX.Element => {
   const defaultMessageBarStyles: IMessageBarStyles = {
     root: {
       height: `${LayoutConstants.rowHeight}px`,
-      overflow: "auto",
+      overflow: "hidden",
+      flexDirection: "row",
     },
   };