TextInputLayout with subscript label hint?

Question

I have a string in my resource file that has a <sub> tag and I want that string to be the hint of my TextInputLayout.

Let the string be:

<string name="fck">f<sub><small>ck</small></sub> [MPa]</string>

And the xml be:

<android.support.design.widget.TextInputLayout
        android:id="@+id/til"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">
        <EditText
            android:id="@+id/textDialog"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:hint="@string/fck"/>
    </android.support.design.widget.TextInputLayout>

The label comes without the subscript in my TextInputLayout. Is it possible to achieve this or is it a library bug and we will need to wait for Google to fix?