Fix behavior of `watch dump`

This CL fixes the behavior of `watch dump` to dump out the tag
monitoring information once and exit, instead of dumping out collected
error traces.

It also reverts the `print` command  back to `live` to better reflect
what the command does.

Bug: 199746421
Test: Tested Manually
Change-Id: If4f9886be0b7db50d43499afbd501bc0d26fc1f4