The Bourne shell, dash shell and other truly POSIX compliant shells
have no mechanism for `set -o pipefail`, thus causing a failure and
termination of deployment steps when being run from those systems.
In particular, Debian and Ubuntu systems see these failures.
This patch explicitly specifies the bash shell, meaning Debian and
Ubuntu systems will not trip up in running this script.
Change-Id: Id52fbbca51a2491346ff979433387c7e695bbb43
Closes-Bug: 1739428
d0ad1ec469