Fix hide text header.

app/src/main/res/layout/expand_header.xml

@@ -16,8 +16,7 @@
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:layout_marginEnd="16dp"
-        android:textAppearance="@style/TextAppearance.Signal.Body1.Bold"
-        android:textStyle="bold"
+        android:textAppearance="@style/Signal.Text.TitleSmall"
         app:layout_constraintEnd_toStartOf="@id/icon"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="parent"