Font size on 'All Chats' was changing mid animation (#2073)

* Font size on 'All Chats' was changing mid animation

changelog.d/1572.bugfix

@@ -0,0 +1 @@
+Font size in 'All Chats' header was changing mid-animation.

features/roomlist/impl/src/main/kotlin/io/element/android/features/roomlist/impl/components/RoomListTopBar.kt

@@ -24,6 +24,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.statusBars
 import androidx.compose.foundation.layout.statusBarsPadding
 import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.material3.TopAppBarScrollBehavior
 import androidx.compose.material3.rememberTopAppBarState
@@ -149,6 +150,20 @@ private fun DefaultRoomListTopBar(
     val statusBarPadding = with(LocalDensity.current) { WindowInsets.statusBars.getTop(this).toDp() }
 
     Box(modifier = modifier) {
+        val collapsedTitleTextStyle = ElementTheme.typography.aliasScreenTitle
+        val expandedTitleTextStyle = ElementTheme.typography.fontHeadingLgBold.copy(
+            // Due to a limitation of MediumTopAppBar, and to avoid the text to be truncated,
+            // ensure that the font size will never be bigger than 28.dp.
+            fontSize = 28.dp.applyScaleDown().toSp()
+        )
+        MaterialTheme(
+            colorScheme = ElementTheme.materialColors,
+            shapes = MaterialTheme.shapes,
+            typography = ElementTheme.materialTypography.copy(
+                headlineSmall = expandedTitleTextStyle,
+                titleLarge = collapsedTitleTextStyle
+            ),
+        ) {
             MediumTopAppBar(
                 modifier = Modifier
                     .onSizeChanged {
@@ -179,18 +194,7 @@ private fun DefaultRoomListTopBar(
                     scrolledContainerColor = Color.Transparent,
                 ),
                 title = {
-                val fontStyle = if (scrollBehavior.state.collapsedFraction > 0.5)
-                    ElementTheme.typography.aliasScreenTitle
-                else
-                    ElementTheme.typography.fontHeadingLgBold.copy(
-                        // Due to a limitation of MediumTopAppBar, and to avoid the text to be truncated,
-                        // ensure that the font size will never be bigger than 28.dp.
-                        fontSize = 28.dp.applyScaleDown().toSp()
-                    )
-                Text(
-                    style = fontStyle,
-                    text = stringResource(id = R.string.screen_roomlist_main_space_title)
-                )
+                    Text(text = stringResource(id = R.string.screen_roomlist_main_space_title))
                 },
                 navigationIcon = {
                     avatarData?.let {
@@ -273,6 +277,7 @@ private fun DefaultRoomListTopBar(
                 scrollBehavior = scrollBehavior,
                 windowInsets = WindowInsets(0.dp),
             )
+        }
 
         HorizontalDivider(
             modifier =