theia-cloud: Make OAuth2 Proxy's allowed redirect domains configurable

[xai]

• Make whitelist_domains and cookie_domains configurable
• Default is the previous behaviour: landing page and session host
• Removes google.com from the default allowed redirects because there is no indication that this is necessary

Fixes eclipse-theia/theia-cloud#357

[jfaltermeier]

LGTM. The only thing I noticed is an extra indent:

{
	"oauth2-proxy.cfg": "# Provider config
		provider=\"keycloak-oidc\"
		redirect_url=\"https://placeholder/oauth2/callback\"
		oidc_issuer_url=\"https://192.168.59.202.nip.io/keycloak/realms/TheiaCloud\"
		ssl_insecure_skip_verify=true
		# Client config
		client_id=\"theia-cloud\"
		client_secret=\"publicbutoauth2proxywantsasecret\"
		cookie_secret=\"s-p4GxfRlPa_BI1XsLuvE2ihNOqYD1vmewWcXcpYjr0=\"
		cookie_secure=\"false\"
		#proxy_prefix=\"\"
		# Upstream config
		http_address=\"0.0.0.0:5000\"
		upstreams=\"http://127.0.0.1:placeholder-port/\"
		# Proxy Config
		#user_id_claim=\"preferred_username\"
		skip_auth_routes=[\"/health.*\"]
		skip_provider_button=\"true\"
		reverse_proxy=\"true\"
		# email_domains=[\"*\"]
		    cookie_domains=[\"ws.192.168.59.202.nip.io\"]
		    whitelist_domains=[\"ws:*\",\"192.168.59.202.nip.io:*\"]
		custom_templates_dir=\"/templates\"
		"
}

It still worked as expected, but if it’s easy to fix, we might want to align it properly.

Also, please bump the chart version.