Add AA51 to validation OOG case (#287)

Author: hazim-j

pkg/gas/estimate.go

@@ -24,6 +24,7 @@ func isPrefundNotPaid(err error) bool {
 func isValidationOOG(err error) bool {
 	return strings.Contains(err.Error(), "AA40 over verificationGasLimit") ||
 		strings.Contains(err.Error(), "AA41 too little verificationGas") ||
+		strings.Contains(err.Error(), "AA51 prefund below actualGasCost") ||
 		strings.Contains(err.Error(), "AA13 initCode failed or OOG") ||
 		strings.Contains(err.Error(), "AA23 reverted (or OOG)") ||
 		strings.Contains(err.Error(), "AA33 reverted (or OOG)") ||