google caldav and carddav

[reafav]

Hello,
Google caldav and carddav are not supported in DAVdroid as I understand. But I really need it.
Maybe someone tried to implement google support in DAVdroid?
And maybe someone know any alternatives of DAVdroid that supports google caldav and carddav api?
I would appreciate any help and information.

[rfc2822]

See also: https://davdroid.bitfire.at/configuration/google/