Add Task and Promise based async templates.
Enable Gradle parallel build and config-on-demand.
Fix the dependency order in the generated IntelliJ IDEA module of data-avro-1_6.

RB=383125
BUGS=SI-1730, TOOLS-47450
R=sfaber,dhoa,si-dev,kvidhani
A=sfaber,dhoa,kvidhani,gogenc