am 9b12b4ed: Fix product-specific string declaration

    <!-- Name of the default audio route when nothing is connected to

         a headphone or other wired audio output jack. [CHAR LIMIT=25] -->

    <string name="default_audio_route_name">Phone speaker</string>

    <string name="default_audio_route_name" product="default">Phone speaker</string>

    <!-- Name of the default audio route for tablets when nothing

         is connected to a headphone or other wired audio output jack. [CHAR LIMIT=25] -->