Various fixes

[hikalium]

List of the changes:

Fixup clippy warnings to pass make commit
Update docs to pass make test
Automatically start ssh forwarding for chrooted commands
Try re-adding the reused addr on cro3 dut list --update
fixup setup commands
Make sure if we have gsutil and gcloud, and it is authenticated
Set stdin null when running repo sync to avoid interactive prompts

[HidenoriKobayashi]

Looking at the change for the sh file, how about we run shellcheck on all of them?

[hikalium]

@HidenoriKobayashi enabled shellcheck and shfmt for all *.sh and *.bash files! Please take a look again!

[hikalium]

@HidenoriKobayashi Please take a look when you have a time. Thank you!

[HidenoriKobayashi]

LGTM. Thanks for integrating the shellcheck check.

[mhiramat]

For the cro3.bash part looks good to me.
Thanks!