Update Gaia API documents for #0659f16b9790b1cf9eba4d80743fcc774d2ffe3a
    Merge pull request #14251 from dominickuo/bug-943797

Bug 943797 - [music] Use hash to decide the default album art, r=jimporter(cherry picked from commit e01827ec7b9bc0426e0f5d216123b9247413db4e)