TS 102 221 Annex A defines three variants of encoding UCS-2 characters
into byte streams in files on UICC cards: One rather simplistic one, and
two variants for optimizing memory utilization on the card.
Let's impelement a construct "Ucs2Adapter" class for this.
Change-Id: Ic8bc8f71079faec1bf0e538dc0dfa21403869c6d