Remove flaky test for cursor drag from presubmit

These tests run fine in isolation (verified both on a physical Pixel 3
and on a Cuttlefish emulator via acloud), but are flaky in presubmits.

Bug: 159628732
Test: Presubmit
Change-Id: Ia27e05543e2647c42e06a684a3ae5c11c074a5fb