MDL-78684 behat: remove tab and set the focus to the user search field

This commit also does few things:
- Adds the I change window size step back to avoid future randoms.
- Increase the download limit size on a couple of download steps that
have been failing randomly.
- Adds missing @core_grades to tertiary_navigation_searching.feature.

admin/tool/dataprivacy/tests/behat/dataexport.feature

@@ -229,7 +229,7 @@ Feature: Data export from the privacy API
     And I reload the page
     And I should see "Download ready" in the "Victim User 1" "table_row"
     And I open the action menu in "Victim User 1" "table_row"
-    And following "Download" should download between "1" and "175000" bytes
+    And following "Download" should download between "1" and "180000" bytes
 
   @javascript
   Scenario: Filter before export data for a user and download it in the view request action
@@ -262,4 +262,4 @@ Feature: Data export from the privacy API
     And I reload the page
     And I should see "Download ready" in the "Victim User 1" "table_row"
     And I open the action menu in "Victim User 1" "table_row"
-    And following "Download" should download between "1" and "175000" bytes
+    And following "Download" should download between "1" and "180000" bytes

grade/report/grader/tests/behat/tertiary_navigation_searching.feature

@@ -1,4 +1,4 @@
-@core @javascript @gradereport @gradereport_grader
+@core @core_grades @javascript @gradereport @gradereport_grader
 Feature: Within the grader report, test that we can search for users
   In order to find specific users in the course gradebook
   As a teacher
@@ -31,6 +31,7 @@ Feature: Within the grader report, test that we can search for users
     And the following config values are set as admin:
       | showuseridentity | idnumber,email,city,country,phone1,phone2,department,institution |
     And I am on the "Course 1" "grades > Grader report > View" page logged in as "teacher1"
+    And I change window size to "large"
 
   Scenario: A teacher can view and trigger the user search
     # Check the placeholder text
@@ -229,9 +230,8 @@ Feature: Within the grader report, test that we can search for users
 
   @accessibility
   Scenario: A teacher can set focus and search using the input are with a keyboard
-    Given I press the tab key
+    Given I set the field "Search users" to "ABC"
     And the focused element is "Search users" "field"
-    And I set the field "Search users" to "ABC"
     And I wait until "Turtle Manatee" "option_role" exists
     # Basic tests for the page.
     When the page should meet accessibility standards

grade/report/singleview/tests/behat/gradeitemsearch.feature

@@ -16,10 +16,10 @@ Feature: Given we have opted to search for a grade item, Lets find and search th
       | activity | course | idnumber | name                |
       | assign   | C1     | a1       | Test assignment one |
       | assign   | C1     | a2       | Test assignment two |
+    And I am on the "Course 1" "grades > Single view > View" page logged in as "teacher1"
 
   Scenario: A teacher can search for and find a grade item to view
-    Given I am on the "Course 1" "grades > Single view > View" page logged in as "teacher1"
-    And I click on "Grade items" "link" in the ".page-toggler" "css_element"
+    Given I click on "Grade items" "link" in the ".page-toggler" "css_element"
     And I click on ".gradesearchwidget" "css_element"
     When I confirm "Test assignment one" in "grade" search within the gradebook widget exists
     And I confirm "Test assignment two" in "grade" search within the gradebook widget exists
@@ -37,8 +37,7 @@ Feature: Given we have opted to search for a grade item, Lets find and search th
   @accessibility
   Scenario: A teacher can set focus and search using the input with a keyboard
     # Basic tests for the page.
-    Given I navigate to "View > Single view" in the course gradebook
-    And I click on "Grade items" "link" in the ".page-toggler" "css_element"
+    Given I click on "Grade items" "link" in the ".page-toggler" "css_element"
     And I click on ".gradesearchwidget" "css_element"
     And the page should meet accessibility standards
     And the page should meet "wcag131, wcag141, wcag412" accessibility standards