prevent the webpage default behavior when dragging in the track content

[ALevansSamsung]

What it does

Perfetto side fix for https://github.com/android-graphics/sokatoa/issues/2392
prevents webpage default behavior when dragging in the track content. This was needed because the default behavior was dragging text content stopping the drag within the track.

How to test

1. Drag Select from left of search in timeline to the main content of the timeline
2. Search and some timeline headers should be highlighted
3. Try to drag select some content in the timeline
4. You're drag in the timeline should not be interrupted in this PR. Try both left to right and right to left.