All users should have read-only access to telemetry opt-in status

[legrego]

In the legacy platform, end-users did not need to read the current telemetry opt-in status, as this was handled server-side by the kibana_system user.

The new platform uses the end-user credentials to retrieve this information, which results in a 403 error for under privileged users. This is common for users with any level of "readonly" access to Kibana.

Kibana's "automatic privilege grants" should be updated so that read-only users also have access to the telemetry saved object type, similar to what we've done for users with all privileges assigned:

kibana/x-pack/plugins/features/server/feature_registry.ts

Lines 50 to 69 in bf04235

	function applyAutomaticAllPrivilegeGrants(
	...allPrivileges: Array<FeatureKibanaPrivileges | undefined>
	) {
	allPrivileges.forEach((allPrivilege) => {
	if (allPrivilege) {
	allPrivilege.savedObject.all = uniq([...allPrivilege.savedObject.all, 'telemetry']);
	allPrivilege.savedObject.read = uniq([...allPrivilege.savedObject.read, 'config', 'url']);
	}
	});
	}
	function applyAutomaticReadPrivilegeGrants(
	...readPrivileges: Array<FeatureKibanaPrivileges | undefined>
	) {
	readPrivileges.forEach((readPrivilege) => {
	if (readPrivilege) {
	readPrivilege.savedObject.read = uniq([...readPrivilege.savedObject.read, 'config', 'url']);
	}
	});
	}

cc @rashmivkulkarni

[elasticmachine]

Pinging @elastic/kibana-security (Team:Security)