Signal-Android/app/src/main/res/layout/media_keyboard.xml

<?xml version="1.0" encoding="utf-8"?>

<merge xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:parentTag="org.thoughtcrime.securesms.components.emoji.MediaKeyboard">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/media_keyboard_fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</merge>