Update pre-install hooks to fail on error
The pre-install operations may fail, yet that failure is not
elevated to the user. This masks the failure and makes early
package install issues difficult to troubleshoot.
If the basic pre-install script fails, the charm should not
proceed to later hooks as the requirements may not be met.
Hashbangs for bash should specify -e (errexit) on all of the
pre-install bash scripts.