Update test selectors to improve test flakiness

[liza-mae]

I am currently running the Kibana UI tests for cloud instance and I had about 22% failures. A lot had to do with the selectors not working and I noticed the following usage which should be changed:

use of .ng-scope, .ng-binding, .ng-hide and nth child

These selectors make the tests flaky / brittle.

We should move towards using data-test-subj.

To temporarily get the tests on cloud to pass I am going to remove the .ng-scope from the tests.

[cjcenizal]

I agree we should be moving away from brittle selectors (e.g. those which depend upon DOM structure or CSS) and to test-specific attributes (data-test-subj).

To temporarily get the tests on cloud to pass I am going to remove the .ng-scope from the tests.

@liza-mae Do we know why this fixes the tests? I may not fully understand the difference between running these tests on a cloud instance vs. locally, but this seems unusual.

[liza-mae]

@cjcenizal I don't know why there is this particular difference between cloud and running locally. I do have failures locally, I just have not had a chance to go through those. Focusing on cloud first. In any case removing the .ng stuff should not break existing tests. It takes 1 and half hours to test the whole suite when trying something, so it takes time for me to get results, but can post once I have them.

[liza-mae]

Although this one is not causing me specific issues, since it was brought up that it may be causing problems. We should move away from using ng-hide or getting .getAttribute('aria-hidden'), selenium isElementPresent function should take care of this for us.
async isGlobalLoadingIndicatorHidden() {
log.debug('isGlobalLoadingIndicatorHidden');
return await find.byCssSelector('[data-test-subj="globalLoadingIndicator"].ng-hide',
defaultFindTimeout * 10);
}

[liza-mae]

Applying the fix for this issue reduced pretty mostly all the failures I was seeing.
There are still 6 failures related to this issue, that can't easily be removed, so I will need to investigate.
The remaining 6 or so issues are assertion failures.

[liza-mae]

Merged #19688, closing.