Fix Test Issue in LKSM (#1176)

* Adding a check to baseReactSelect.removeSelection to validate that selection was removed.

Author: labkey-danield

src/org/labkey/test/components/react/BaseReactSelect.java

@@ -255,10 +255,15 @@ public T removeSelection(String value)
 
         scrollIntoView();
 
-        var removeBtn = Locators.removeMultiSelectValueButton(value).waitForElement(getComponentElement(), 1_500);
+        WebElement removeBtn = Locators.removeMultiSelectValueButton(value).findWhenNeeded(getComponentElement());
         removeBtn.click();
+
         getWrapper().shortWait().until(ExpectedConditions.stalenessOf(removeBtn));
 
+        // Validate that the selected item really was removed.
+        WebDriverWrapper.sleep(500);
+        waitFor(()->!getSelections().contains(value), String.format("Failed to remove selection '%s'.", value), WAIT_FOR_JAVASCRIPT);
+
         return getThis();
     }