Limit init container capabilities

[sjberman]

In order to ensure security and limit unnecessary access, our init container should be limited in the capabilities that it has. This should be similar to what our existing containers already have in place.

A/C:

• init container only has the permissions necessary to function

[ja20222]

This ticket may not be needed depending on the outcome of this discussion #754

[kate-osborn]

Closing since init container will be removed once #934 is merged