Wrong encoding for sms messages sent by coding=8 in Persian or Arabic Languages

[majidshirazy]

Hello
The Messages sent by api with the content of Persian or Arabic using coding=8 in the api request body, are now encoded into utf16 and then sent through upstream smpp gateways.
These languages are needed to encode / decode in UTF8 to show the correct content.

For example:
The content of this message was "تست" but has been received as ��� on the mobile phone.