Lower the retry count in download fetcher if the update is interactive.

Retrying 20 times could take a very long time, which we don't want in
an interactive update.

Bug: 70722687
Test: only retried 3 times
Change-Id: Ic9551ab3f3603a299cda0caa961e5e4109bb05b8
(cherry picked from commit d77408d2a75c31ab0541f3a23a3ccad1092ffd77)