fix(encoding/form): time with the location set to local time

encoding/form/well_known_types.go

@@ -52,7 +52,7 @@ func marshalTimestamp(m protoreflect.Message) (string, error) {
 	}
 	// Uses RFC 3339, where generated output will be Z-normalized and uses 0, 3,
 	// 6 or 9 fractional digits.
-	t := time.Unix(secs, nanos).UTC()
+	t := time.Unix(secs, nanos).Local()
 	x := t.Format("2006-01-02T15:04:05.000000000")
 	x = strings.TrimSuffix(x, "000")
 	x = strings.TrimSuffix(x, "000")

encoding/form/well_known_types_test.go

@@ -17,11 +17,11 @@ func TestMarshalTimeStamp(t *testing.T) {
 		expect string
 	}{
 		{
-			input:  timestamppb.New(time.Date(2022, 1, 2, 3, 4, 5, 6, time.UTC)),
+			input:  timestamppb.New(time.Date(2022, 1, 2, 3, 4, 5, 6, time.Local)),
 			expect: "2022-01-02T03:04:05.000000006Z",
 		},
 		{
-			input:  timestamppb.New(time.Date(2022, 13, 1, 13, 61, 61, 100, time.UTC)),
+			input:  timestamppb.New(time.Date(2022, 13, 1, 13, 61, 61, 100, time.Local)),
 			expect: "2023-01-01T14:02:01.000000100Z",
 		},
 	}