Send timezone update message on initial login

Piggybacks on the AppRTCClient VideoParameterGetter async task. Right
after sending the VIDEO_PARAMS request, it sends another request with
type TIMEZONE containing the local default timezone ID string.

Requires the following commits in the protocol and svmpd:
protocol-def >= 7a56c1175b33236d7ba21fc27c3044e1e49e7aa4
svmp >= b64b724fe65620c19ea01cd82b5886e1c5b66efe

Change-Id: I119fdd0d4bdb0c99df05f60bf54b931dff898583