Yes, I know that eventually what now is known as "tail_build" will be
all there is left. So by that time, by definition nothing can be built
"after tail_build". Will have to handle that then.
Change-Id: I47d228ca7156520db10630861ce52b015a7a169c
Serialize the Ant cleaning and building of android/abs-lib so that one
Ant is not cleaning it while another is building something that
depends on it.
Change-Id: I22fde47bf84208fa129b8f6a65a2314c885451a0