[Bug] Missing "Album artist-album" French translation

[remjg]

In French, on of the pref_library_grouping_values translation is missing, the one for albumartist-album.

Hence, the options don't correspond to the correct grouping features of the library, and the last option is also missing.

Looking at the /app/src/main/res/values/array.xml file, there should be 7 options in the following order :

<string-array name="pref_library_grouping_values">
        <item>artist</item>
        <item>artist-album</item>
        <item>albumartist-album</item>
        <item>artist-year</item>
        <item>album</item>
        <item>genre-album</item>
        <item>genre-artist-album</item>
</string-array>

I think that this problem is present in others languages too where I can only see 6 options. Not sure my pull request answer the issue completely, I have never looked into how translations work.