Mark ViewGroupScrollCaptureTest as non-flaky

Allows these tests to run in presubmit
Verified 100% flake-free:
   https://paste.googleplex.com/6331441450319872

Bug: 175830396
Test: atest --rerun-until-failure 10 ViewGroupScrollCaptureTest
Change-Id: Ibf278c929f331f9ac6a9ba0630f3f375f4f21b7c