APPLIED: [PATCH 0/6 Xenial SRU] Fix derivatives build after tools-common removal

[Thadeu Lima de Souza Cascardo]

Applied first patch to aws, gke, raspi2, snapdragon and lts-xenial
branches. Also applied to xenial master-next branch. Other patches to
their respective branches: aws, gke, raspi2 and snapdragon. lts-xenial
already had do_tools_common=false in its hooks.mk.

Thanks.
Cascardo.