Disable stylus integration tests temporarily

These tests are failing regularly on presubmit and is affecting
development velocity. Even though their failure rate is relatively low
(below 5%) on postsubmit runs, we'll disable these tests for now until
we can debug the issue.

They can be included in local runs by using the following gtest flag:
    --gunit_also_run_disabled_tests

Bug: 261025260
Test: Presubmit
Change-Id: I991bf9b1431dcdbfe2017207c0b06cb8bcce7c70