home: Expand tap area for correct feedback.

Added Gesture Detector over Column, Temporary
set the onPressed of the Icon Button to null.

Fixes: zulip#1808

Author: MritunjayTiwari14

lib/widgets/home.dart

@@ -264,31 +264,36 @@ class _NavigationBarButton extends StatelessWidget {
     return AnimatedScaleOnTap(
       scaleEnd: 0.875,
       duration: const Duration(milliseconds: 100),
-      child: Column(
-        children: [
-          SizedBox(
-            height: 34,
-            child: IconButton(
-              icon: Icon(icon, size: 24),
-              onPressed: onPressed,
-              style: IconButton.styleFrom(
-                // TODO(#417): Disable splash effects for all buttons globally.
-                splashFactory: NoSplash.splashFactory,
-                highlightColor: designVariables.navigationButtonBg,
-                shape: const RoundedRectangleBorder(
-                  borderRadius: BorderRadius.all(Radius.circular(4))),
-              ).copyWith(foregroundColor: iconColor)),
-          ),
-          Text(
-            label,
-            style: TextStyle(
-              fontSize: 12,
-              color: textColor,
-              height: 1.0,),
-            textAlign: TextAlign.center,
-            maxLines: 2,
-            overflow: TextOverflow.ellipsis)
-        ]));
+      child: GestureDetector(
+        onTap: onPressed,
+        child: Column(
+          children: [
+            SizedBox(
+              height: 34,
+              child: IconButton(
+                icon: Icon(icon, size: 24),
+                onPressed: null,
+                style: IconButton.styleFrom(
+                  // TODO(#417): Disable splash effects for all buttons globally.
+                  splashFactory: NoSplash.splashFactory,
+                  highlightColor: designVariables.navigationButtonBg,
+                  shape: const RoundedRectangleBorder(
+                    borderRadius: BorderRadius.all(Radius.circular(4))),
+                ).copyWith(foregroundColor: iconColor)),
+            ),
+            Expanded(
+              child: Text(
+                label,
+                style: TextStyle(
+                  fontSize: 12,
+                  color: textColor,
+                  height: 1.0,),
+                textAlign: TextAlign.center,
+                maxLines: 2,
+                overflow: TextOverflow.ellipsis),
+            )
+          ]),
+      ));
   }
 }