[MM-42878] Allow + in the timestamp for mlog tests (#20360)

shared/mlog/global_test.go

@@ -128,12 +128,12 @@ func TestLoggingAfterInitialized(t *testing.T) {
 				actual := strings.TrimSpace(string(logs))
 
 				if testCase.cfg.Format == "json" {
-					reTs := regexp.MustCompile(`"timestamp":"[0-9\.\-\:\sZ]+"`)
+					reTs := regexp.MustCompile(`"timestamp":"[0-9\.\-\+\:\sZ]+"`)
 					reCaller := regexp.MustCompile(`"caller":"([^"]+):[0-9\.]+"`)
 					actual = reTs.ReplaceAllString(actual, `"timestamp":0`)
 					actual = reCaller.ReplaceAllString(actual, `"caller":"$1:0"`)
 				} else {
-					reTs := regexp.MustCompile(`\[\d\d\d\d-\d\d-\d\d\s[0-9\:\.\s\-Z]+\]`)
+					reTs := regexp.MustCompile(`\[\d\d\d\d-\d\d-\d\d\s[0-9\:\.\s\-\+Z]+\]`)
 					reCaller := regexp.MustCompile(`caller="([^"]+):[0-9\.]+"`)
 					actual = reTs.ReplaceAllString(actual, "TIME")
 					actual = reCaller.ReplaceAllString(actual, `caller="$1:0"`)