Insurance — Homeowners — Water intrusion into home caused by septic tank backup — Trial court did not err in entering final summary judgment for insurer based on conclusion that insureds failed to overcome presumption that their failure to timely report claim had prejudiced insurer’s investigation — Although there may have been disputed issues of fact as to whether insurer was prejudiced in determining cause of loss, facts, even as presented by insured’s adjuster and engineer, showed that insurer would be prejudiced by passage of time in investigating extent of loss, and thus, the cost of repair