This is the new file I use:
<?xml version="1.0" encoding="UTF-8"?>
<provider id="google">
<name>Google</name>
<description>GNOME-ID, Google Drive and YouTube</description>
<icon>im-google</icon>
<translations>kaccounts-providers</translations>
<domains>.*google\.com</domains>
<template>
<group name="auth">
<setting name="method">oauth2</setting>
<setting name="mechanism">web_server</setting>
<group name="oauth2">
<group name="web_server">
<setting name="Host">accounts.google.com</setting>
<setting name="AuthPath">o/oauth2/auth?access_type=offline</setting>
<setting name="TokenPath">o/oauth2/token</setting>
<setting name="RedirectUri">http://localhost/oauth2callback</setting>
<setting name="ResponseType">code</setting>
<setting type="as" name="Scope">[
'https://www.googleapis.com/auth/userinfo.email',
'https://www.googleapis.com/auth/userinfo.profile',
'https://www.googleapis.com/auth/calendar',
'https://www.googleapis.com/auth/tasks',
'https://www.googleapis.com/auth/drive'
]</setting>
<setting type="as" name="AllowedSchemes">['https']</setting>
<setting name="ClientId">44438659992-7kgjeitenc16ssihbtdjbgguch7ju55s.apps.googleusercontent.com</setting>
<setting name="ClientSecret">-gMLuQyDiI0XrQS_vx_mhuYF</setting>
<setting type="b" name="ForceClientAuthViaRequestBody">true</setting>
</group>
</group>
</group>
</template>
</provider>