Revert "[mob][photos] Add shadow to home tab's app bar"

This reverts commit 3461201708.

mobile/lib/ui/home/error_warning_header_widget.dart

@@ -7,6 +7,7 @@ import 'package:photos/events/notification_event.dart';
 import 'package:photos/events/sync_status_update_event.dart';
 import "package:photos/generated/l10n.dart";
 import 'package:photos/services/user_remote_flag_service.dart';
+import "package:photos/theme/ente_theme.dart";
 import 'package:photos/ui/account/verify_recovery_page.dart';
 import 'package:photos/ui/components/notification_widget.dart';
 import 'package:photos/ui/home/header_error_widget.dart';
@@ -66,6 +67,12 @@ class _ErrorWarningHeaderState extends State<ErrorWarningHeader> {
   Widget build(BuildContext context) {
     return Column(
       children: [
+        _showErrorBanner
+            ? Divider(
+                height: 8,
+                color: getEnteColorScheme(context).strokeFaint,
+              )
+            : const SizedBox.shrink(),
         _showErrorBanner
             ? HeaderErrorWidget(error: _syncError)
             : const SizedBox.shrink(),

mobile/lib/ui/home/home_app_bar_widget.dart

@@ -76,13 +76,7 @@ class _HomeAppBarWidgetState extends State<HomeAppBarWidget> {
 
   @override
   AppBar build(BuildContext context) {
-    final colorScheme = getEnteColorScheme(context);
     return AppBar(
-      backgroundColor: colorScheme.backgroundElevated,
-      elevation: 4,
-      surfaceTintColor: Colors.transparent,
-      shadowColor: Colors.black.withOpacity(0.2),
-      clipBehavior: Clip.none,
       centerTitle: true,
       title: AnimatedSwitcher(
         duration: const Duration(milliseconds: 500),