[Security Solutions] Fix flaky entity analytics dashboard risk filter…

… cypress tests (elastic#174838)

Implement the same solution proposal by Jared here
elastic#173970

## Summary

flaky tests:
elastic#174260
elastic#174102

flaky test runner (300 runs)
https://buildkite.com/elastic/kibana-flaky-test-suite-runner/builds/4864

### Checklist

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

x-pack/test/security_solution_cypress/cypress/e2e/entity_analytics/dashboards/entity_analytics.cy.ts

@@ -370,7 +370,10 @@ describe('Entity Analytics Dashboard', { tags: ['@ess', '@serverless'] }, () =>
         });
 
         it('filters by risk level', () => {
+          cy.get(HOSTS_TABLE).should('be.visible');
+          cy.get(HOSTS_TABLE_ROWS).should('have.length', 5);
           cy.get(HOSTS_DONUT_CHART).should('include.text', '6Total');
+
           openRiskTableFilterAndSelectTheCriticalOption();
 
           cy.get(HOSTS_DONUT_CHART).should('include.text', '1Total');
@@ -461,6 +464,8 @@ describe('Entity Analytics Dashboard', { tags: ['@ess', '@serverless'] }, () =>
 
         it('filters by risk level', () => {
           cy.get(USERS_DONUT_CHART).should('include.text', '7Total');
+          cy.get(USERS_TABLE).should('be.visible');
+          cy.get(USERS_TABLE_ROWS).should('have.length', 5);
 
           openUserRiskTableFilterAndSelectTheLowOption(1);