Set umask to 0 while creating directory at untar

[k311093]

While creating a directory at untarring artifacts, there is a possibility to create a directory not with permissions 0774.

This causes _cvd-executor failing to create a lock file for an image and then fails to execute cvd.

Set umask 0 while creating directory at untarring to create directory with proper permissions.

[ser-io]

let's squash all these commits into one for this PR.

this way we avoid having the defer issue introduced in 0d2aa01 (fixed later at d9bd9a7) in our history.

[k311093]

Squashed all commits into one