Update OkHttp to latest version. (#1564)
Update OkHttp to latest version. (#1564)

Update to latest version in 3.12.x series, as we don't want to bump min
required SDK version at this point.

Signed-off-by: Danny Baumann <4bceda912b479e46f041c22bcc2c9ed75fe8d5cc@web.de>
openhab/openhab.android