MM-44420 - replace 14-day references with new freemium 30-day (#20349)

Co-authored-by: Pablo Velez Vidal <pablo.velez@mattermost.com>

app/email/email_test.go

@@ -252,7 +252,7 @@ func TestSendCloudTrialEndedEmail(t *testing.T) {
 			require.Contains(t, resultsMailbox[0].To[0], emailTo, "Wrong To: recipient")
 			resultsEmail, err := mail.GetMessageFromMailbox(emailTo, resultsMailbox[0].ID)
 			require.NoError(t, err, "Could not get message from mailbox")
-			require.Contains(t, resultsEmail.Body.Text, "Your free 14-day trial of Mattermost has ended", "Wrong received message %s", resultsEmail.Body.Text)
+			require.Contains(t, resultsEmail.Body.Text, "Your free 30-day trial of Mattermost has ended", "Wrong received message %s", resultsEmail.Body.Text)
 		}
 		mail.DeleteMailBox(emailTo)