Signal-Android/res/layout/enter_backup_passphrase_dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="16dp">

    <com.google.android.material.textfield.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/restore_passphrase_input"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fontFamily="monospace"
            android:hint="@string/enter_backup_passphrase_dialog__backup_passphrase"
            android:imeOptions="actionDone"
            android:inputType="number"
            android:maxLength="30"
            android:textSize="16sp" />

    </com.google.android.material.textfield.TextInputLayout>

</FrameLayout>