builtin-extensions: remove EngineEncryptionUtils usage

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1120720
Change-Id: Ic4a2d8927729223c710dfe43c07b85ccbc9b5d56
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>