Implement update_engine weave commands
The new WeaveServiceInterface abstracs the registration and interaction
with weave whenever present. The compilation and usage of weave is
based on the BRILLO_USE_WEAVE flag.
When enabled, update_engine registers the "_updater" component with
methods to force-check for an update and change channels.
Bug: 24386758
Bug: 24386768
Test: Deployed on edison, weave commands and state available online.
Change-Id: Ic49111772e123b8a2b1971da92fe65785f186ccd
16 files changed