Enable fullscreen button in call

GitLab: #178
Change-Id: I9e3e1491c9645efe7b5aa4bbd1550f7a19b0b36c
diff --git a/client/src/components/CallButtons.tsx b/client/src/components/CallButtons.tsx
index b127a77..404bfae 100644
--- a/client/src/components/CallButtons.tsx
+++ b/client/src/components/CallButtons.tsx
@@ -118,7 +118,17 @@
 };
 
 export const CallingFullScreenButton = (props: ExpandableButtonProps) => {
-  return <CallButton aria-label="full screen" Icon={FullScreenIcon} {...props} />;
+  const { setIsFullscreen } = useContext(CallContext);
+  return (
+    <CallButton
+      aria-label="full screen"
+      Icon={FullScreenIcon}
+      onClick={() => {
+        setIsFullscreen((v) => !v);
+      }}
+      {...props}
+    />
+  );
 };
 
 export const CallingGroupButton = (props: ExpandableButtonProps) => {