[tab resume] Make the random default result disabled by default

The existing resumption would use the default model and not
for training, so return recent result for these cases.

Change-Id: Ic0d56059c2960739a686a2ca95b66432b9086285
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5627660
Reviewed-by: Ritika Gupta <ritikagup@google.com>
Commit-Queue: Siddhartha S <ssid@chromium.org>
Auto-Submit: Siddhartha S <ssid@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1314204}