Send vCard with Unicode encoded Strings over BT

The standard Android code doesn't correctly handle creation of byte
packets when sending vCard data.  The length of a String is used to
specify the number of bytes being sent, which works if all
characters are ASCII (1 byte per char), but if Unicode characters
exist within the string, then bytes vs String length differ which
causes a truncation of the vCard during Bluetooth send.

Change-Id: Ic39dd53a38f1f353523c625940b0317b00e86d4f