Fix deprecations

lib/views/chat.dart

@@ -407,7 +407,7 @@ class _ChatState extends State<_Chat> {
                 child: Icon(Icons.arrow_downward,
                     color: Theme.of(context).primaryColor),
                 onPressed: () => _scrollController.jumpTo(0),
-                foregroundColor: Theme.of(context).textTheme.body1.color,
+                foregroundColor: Theme.of(context).textTheme.bodyText2.color,
                 backgroundColor: Theme.of(context).scaffoldBackgroundColor,
                 mini: true,
               ),

lib/views/chat_details.dart

@@ -186,8 +186,11 @@ class _ChatDetailsState extends State<ChatDetails> {
               ],
               title: Text(widget.room.getLocalizedDisplayname(I18n.of(context)),
                   style: TextStyle(
-                      color:
-                          Theme.of(context).appBarTheme.textTheme.title.color)),
+                      color: Theme.of(context)
+                          .appBarTheme
+                          .textTheme
+                          .headline6
+                          .color)),
               backgroundColor: Theme.of(context).appBarTheme.color,
               flexibleSpace: FlexibleSpaceBar(
                 background: ContentBanner(widget.room.avatar,
@@ -223,7 +226,7 @@ class _ChatDetailsState extends State<ChatDetails> {
                           linkStyle: TextStyle(color: Colors.blueAccent),
                           textStyle: TextStyle(
                             fontSize: 14,
-                            color: Theme.of(context).textTheme.body1.color,
+                            color: Theme.of(context).textTheme.bodyText2.color,
                           ),
                         ),
                         onTap: widget.room.canSendEvent("m.room.topic")

lib/views/chat_encryption_settings.dart

@@ -112,7 +112,8 @@ class _ChatEncryptionSettingsState extends State<ChatEncryptionSettings> {
                               .keys["ed25519:${deviceKeys[i].deviceId}"]
                               .beautified,
                           style: TextStyle(
-                              color: Theme.of(context).textTheme.body1.color),
+                              color:
+                                  Theme.of(context).textTheme.bodyText2.color),
                         ),
                         value: deviceKeys[i].verified,
                         onChanged: (bool newVal) {

lib/views/settings.dart

@@ -149,7 +149,11 @@ class _SettingsState extends State<Settings> {
               title: Text(
                 I18n.of(context).settings,
                 style: TextStyle(
-                    color: Theme.of(context).appBarTheme.textTheme.title.color),
+                    color: Theme.of(context)
+                        .appBarTheme
+                        .textTheme
+                        .headline6
+                        .color),
               ),
               background: ContentBanner(
                 profile?.avatarUrl,