[Synthetics] Unskip Uptime overview page functional tests (#163985)

## Summary

Updates and unskips the overview page tests.

Resolves #89072.

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
Co-authored-by: Shahzad <shahzad31comp@gmail.com>

x-pack/test/functional/apps/uptime/overview.ts

@@ -17,8 +17,7 @@ export default ({ getPageObjects, getService }: FtrProviderContext) => {
 
   const testSubjects = getService('testSubjects');
 
-  // FLAKY: https://github.com/elastic/kibana/issues/89072
-  describe.skip('overview page', function () {
+  describe('overview page', function () {
     const DEFAULT_DATE_START = 'Sep 10, 2019 @ 12:40:08.078';
     const DEFAULT_DATE_END = 'Sep 11, 2019 @ 19:40:08.078';
 
@@ -199,7 +198,7 @@ export default ({ getPageObjects, getService }: FtrProviderContext) => {
 
       it('can change query syntax to kql', async () => {
         await testSubjects.click('switchQueryLanguageButton');
-        await testSubjects.click('languageToggle');
+        await testSubjects.click('kqlLanguageMenuItem');
       });
 
       it('runs filter query without issues', async () => {

x-pack/test/functional/services/uptime/common.ts

@@ -45,7 +45,7 @@ export function UptimeCommonProvider({ getService, getPageObjects }: FtrProvider
       await this.setKueryBarText('queryInput', filterQuery);
     },
     async goToNextPage() {
-      await testSubjects.click('xpack.synthetics.monitorList.nextButton', 5000);
+      await testSubjects.click('xpack.uptime.monitorList.nextButton', 5000);
     },
     async goToPreviousPage() {
       await testSubjects.click('xpack.synthetics.monitorList.prevButton', 5000);
@@ -97,11 +97,11 @@ export function UptimeCommonProvider({ getService, getPageObjects }: FtrProvider
       };
     },
     async openPageSizeSelectPopover(): Promise<void> {
-      return testSubjects.click('xpack.synthetics.monitorList.pageSizeSelect.popoverOpen', 5000);
+      return testSubjects.click('xpack.uptime.monitorList.pageSizeSelect.popoverOpen', 5000);
     },
     async clickPageSizeSelectPopoverItem(size: number = 10): Promise<void> {
       return testSubjects.click(
-        `xpack.synthetics.monitorList.pageSizeSelect.sizeSelectItem${size.toString()}`,
+        `xpack.uptime.monitorList.pageSizeSelect.sizeSelectItem${size.toString()}`,
         5000
       );
     },