[Backport staging] Fix video body interaction (#34163)

Co-authored-by: Zack <zazi21@student.bth.se>

packages/shared-components/src/room/timeline/event-tile/body/MVideoBodyView/VideoBodyView.module.css

@@ -8,6 +8,7 @@
 }
 
 .video {
+    position: relative;
     display: block;
     width: 100%;
     height: 100%;

packages/shared-components/src/room/timeline/event-tile/body/MVideoBodyView/VideoBodyView.test.tsx

@@ -112,6 +112,7 @@ describe("VideoBodyView", () => {
         );
 
         const video = screen.getByLabelText("Product demo video") as HTMLVideoElement;
+        expect(video).toHaveStyle({ position: "relative" });
         expect(video).toHaveAttribute("src", "https://example.org/demo.mp4");
         expect(video).toHaveAttribute("poster", "https://example.org/demo-poster.jpg");
         expect(video).toHaveAttribute("preload", "none");