Improve create proposal code (#8586)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

x/gov/types/proposal.go

@@ -18,15 +18,6 @@ const DefaultStartingProposalID uint64 = 1
 
 // NewProposal creates a new Proposal instance
 func NewProposal(content Content, id uint64, submitTime, depositEndTime time.Time) (Proposal, error) {
-	p := Proposal{
-		ProposalId:       id,
-		Status:           StatusDepositPeriod,
-		FinalTallyResult: EmptyTallyResult(),
-		TotalDeposit:     sdk.NewCoins(),
-		SubmitTime:       submitTime,
-		DepositEndTime:   depositEndTime,
-	}
-
 	msg, ok := content.(proto.Message)
 	if !ok {
 		return Proposal{}, fmt.Errorf("%T does not implement proto.Message", content)
@@ -37,6 +28,15 @@ func NewProposal(content Content, id uint64, submitTime, depositEndTime time.Tim
 		return Proposal{}, err
 	}
 
+	p := Proposal{
+		ProposalId:       id,
+		Status:           StatusDepositPeriod,
+		FinalTallyResult: EmptyTallyResult(),
+		TotalDeposit:     sdk.NewCoins(),
+		SubmitTime:       submitTime,
+		DepositEndTime:   depositEndTime,
+	}
+
 	p.Content = any
 
 	return p, nil