Add Delay to unstable tests (#11638)

* Add Delay to unstable tests

* Add sleep time

uitest/src/test/java/com/vaadin/tests/components/datefield/DateTimeFieldEventOrderTest.java

         new Select(timeSelects.get(0)).selectByValue("09");
 
         findElement(By.id("test-button")).click();
+        sleep(100);
 
         assertEquals("The button click event should come second.",
                 "2. Button Click Event", getLogRow(0));

uitest/src/test/java/com/vaadin/tests/components/datefield/DateTimeFieldWeekDaysTest.java

 package com.vaadin.tests.components.datefield;
 
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
 import org.junit.Test;
 import org.openqa.selenium.WebElement;
 import org.openqa.selenium.support.ui.ExpectedConditions;
 import com.vaadin.testbench.elements.DateTimeFieldElement;
 import com.vaadin.tests.tb3.SingleBrowserTest;
 
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
 public class DateTimeFieldWeekDaysTest extends SingleBrowserTest {
 
     @Test
 
         openPopupAndValidateNoWeeknumbers();
 
+
         $(ButtonElement.class).id("finnish").click();
 
         openPopupAndValidateWeekNumbers();
                 .findElement(By.className("v-datefield-button"));
         // Open date popup
         popupButton.click();
-
+        sleep(100);
+        
         waitUntil(ExpectedConditions.visibilityOfElementLocated(
                 org.openqa.selenium.By.className("v-datefield-popup")));
 
                                 .isEmpty());
         // Close popup
         popupButton.click();
+        sleep(100);
     }
 
     private void openPopupAndValidateNoWeeknumbers() {
                 .findElement(By.className("v-datefield-button"));
         // Open date popup
         popupButton.click();
+        sleep(100);
 
         waitUntil(ExpectedConditions.visibilityOfElementLocated(
                 org.openqa.selenium.By.className("v-datefield-popup")));
                                 .isEmpty());
         // Close popup
         popupButton.click();
+        sleep(100);
     }
 }

uitest/src/test/java/com/vaadin/tests/components/ui/TextAreaEventPropagationTest.java

         builder2.click(textField);
 
         builder2.sendKeys("third line");
+        sleep(100);
         builder2.sendKeys(Keys.ENTER);
+        sleep(100);
         builder2.sendKeys(Keys.ESCAPE);
-
         builder2.perform();
 
         assertEquals("1. Enter button pressed", getLogRow(1));