FIX: Integration tests CI instability on Integration_CanSendAndReceiveEvents

[jfreire-unity]

Description

This PR fixes the CI instability reported in ISX-1381, where Integration_CanSendAndReceiveEvents would fail.

Changes made

Locally, the test failed because sometimes the device state was not updated. This was because the device was seen as "disabled"), thus not updating its state. The reason why the device was disabled is that sometimes the test player didn't have "game focus" (see [1] and [2].)

On macOS, I've seen this happening due to the "accept incoming connection" pop-up, and on Windows a similar pop-up appeared.
By setting the background behavior settings to InputSettings.BackgroundBehavior.IgnoreFocus, the test always passed locally.

Notes

Please write down any additional notes, remove the section if not applicable.

Checklist

Before review:

• Changelog entry added.
  • Explains the change in Changed, Fixed, Added sections.
  • For API change contains an example snippet and/or migration example.
  • FogBugz ticket attached, example ([case %number%](https://issuetracker.unity3d.com/issues/...)).
  • FogBugz is marked as "Resolved" with next release version correctly set.
• Tests added/changed, if applicable.
  • Functional tests Area_CanDoX, Area_CanDoX_EvenIfYIsTheCase, Area_WhenIDoX_AndYHappens_ThisIsTheResult.
  • Performance tests.
  • Integration tests.
• Docs for new/changed API's.
  • Xmldoc cross references are set correctly.
  • Added explanation how the API works.
  • Usage code examples added.
  • The manual is updated, if needed.

During merge:

• Commit message for squash-merge is prefixed with one of the list:
  • NEW: ___.
  • FIX: ___.
  • DOCS: ___.
  • CHANGE: ___.
  • RELEASE: 1.1.0-preview.3.

[lyndon-unity]

Looks like a nice targeted fix for the issue. Thank you.