Replace empty Contains with SizedBox.shrink

lib/ui/account/password_entry_page.dart

@@ -101,7 +101,7 @@ class _PasswordEntryPageState extends State<PasswordEntryPage> {
       resizeToAvoidBottomInset: isKeypadOpen,
       appBar: AppBar(
         leading: widget.mode == PasswordEntryMode.reset
-            ? Container()
+            ? const SizedBox.shrink()
             : IconButton(
                 icon: const Icon(Icons.arrow_back),
                 color: Theme.of(context).iconTheme.color,
@@ -142,7 +142,7 @@ class _PasswordEntryPageState extends State<PasswordEntryPage> {
       passwordStrengthColor = Colors.orangeAccent;
     }
     if (_volatilePassword != null) {
-      return Container();
+      return const SizedBox.shrink();
     }
     return Column(
       children: [

lib/ui/huge_listview/scroll_bar_thumb.dart

@@ -143,7 +143,7 @@ class SlideFadeTransition extends StatelessWidget {
     return AnimatedBuilder(
       animation: animation!,
       builder: (context, child) =>
-          animation!.value == 0.0 ? Container() : child!,
+          animation!.value == 0.0 ? const SizedBox.shrink() : child!,
       child: SlideTransition(
         position: Tween(
           begin: const Offset(0.3, 0.0),

lib/ui/payment/payment_web_page.dart

@@ -63,7 +63,7 @@ class _PaymentWebPageState extends State<PaymentWebPage> {
           children: <Widget>[
             (progress != 1.0)
                 ? LinearProgressIndicator(value: progress)
-                : Container(),
+                : const SizedBox.shrink(),
             Expanded(
               child: InAppWebView(
                 initialUrlRequest: URLRequest(url: initPaymentUrl),

lib/ui/settings/app_version_widget.dart

@@ -46,7 +46,7 @@ class _AppVersionWidgetState extends State<AppVersionWidget> {
               ),
             );
           }
-          return Container();
+          return const SizedBox.shrink();
         },
       ),
     );

lib/ui/settings/backup/backup_folder_selection_page.dart

@@ -109,7 +109,7 @@ class _BackupFolderSelectionPageState extends State<BackupFolderSelectionPage> {
             padding: EdgeInsets.all(10),
           ),
           _deviceCollections == null
-              ? Container()
+              ? const SizedBox.shrink()
               : GestureDetector(
                   behavior: HitTestBehavior.translucent,
                   child: Padding(

lib/ui/tabs/shared/incoming_album_item.dart

@@ -90,7 +90,7 @@ class IncomingAlbumItem extends StatelessWidget {
                       ),
                     );
                   } else {
-                    return Container();
+                    return const SizedBox.shrink();
                   }
                 },
               ),

lib/ui/tabs/shared/outgoing_album_item.dart

@@ -80,11 +80,11 @@ class OutgoingAlbumItem extends StatelessWidget {
                                   color: warning500,
                                 )
                               : const Icon(Icons.link))
-                          : Container(),
+                          : const SizedBox.shrink(),
                     ],
                   ),
                   shareesName.isEmpty
-                      ? Container()
+                      ? const SizedBox.shrink()
                       : Padding(
                           padding: const EdgeInsets.fromLTRB(0, 4, 0, 0),
                           child: Text(

lib/ui/tools/deduplicate_page.dart

@@ -309,7 +309,7 @@ class _DeduplicatePageState extends State<DeduplicatePage> {
       mainAxisAlignment: MainAxisAlignment.spaceBetween,
       crossAxisAlignment: CrossAxisAlignment.end,
       children: [
-        Container(),
+        const SizedBox.shrink(),
         PopupMenuButton(
           initialValue: sortKey.index,
           child: Padding(

lib/ui/viewer/gallery/trash_page.dart

@@ -111,7 +111,7 @@ class TrashPage extends StatelessWidget {
             ),
           );
         } else {
-          return Container();
+          return const SizedBox.shrink();
         }
       },
     );