Add message_style.xml

app/src/main/res/values/message_style.xml

+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <style name="TextAppearance.RocketChat.Message.Day" parent="TextAppearance.AppCompat">
+        <item name="android:textSize">12sp</item>
+        <item name="android:textColor">@color/colorPrimaryTextDark</item>
+    </style>
+
+    <style name="TextAppearance.RocketChat.Message.SubUsername" parent="TextAppearance.AppCompat.Body1">
+        <item name="android:textColor">#5f000000</item>
+    </style>
+
+    <style name="TextAppearance.RocketChat.Message.Username" parent="TextAppearance.AppCompat.Body2">
+        <item name="android:textColor">@color/colorPrimaryTextDark</item>
+        <item name="android:textSize">14sp</item>
+        <item name="android:maxLines">1</item>
+        <item name="android:ellipsize">end</item>
+    </style>
+</resources>
\ No newline at end of file