[iOS] Add IOSDownloadOpenInDriveApp user action

This CL adds a `IOSDownloadOpenInDriveApp` user action triggered when
the user taps "OPEN" in the download manager UI after a download to
Drive successfully completed.

Bug: 333039131
Change-Id: I33c914c1fb5acab7d6a661180f557340be667bde
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5424797


Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: Quentin Pubert <qpubert@google.com>
Reviewed-by: Ewann Pellé <ewannpv@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1283103}