Feature/search domain for android (#1256)

Support search domain on Android

- pass list of search domains to Android SDK
- throw notification in case of search domain changes

client/internal/dns/mockServer.go

@@ -2,6 +2,7 @@ package dns
 
 import (
 	"fmt"
+
 	nbdns "github.com/netbirdio/netbird/dns"
 )
 
@@ -43,3 +44,7 @@ func (m *MockServer) UpdateDNSServer(serial uint64, update nbdns.Config) error {
 	}
 	return fmt.Errorf("method UpdateDNSServer is not implemented")
 }
+
+func (m *MockServer) SearchDomains() []string {
+	return make([]string, 0)
+}