* Upgrade error-prone to 3.3.4
This would fix the failure with openjdk 11.0.9 in
3.3.3.
Fixed new antipatterns raised by the new version:
- Replaced unnecessary lambdas with methods.
- Switched wait/sleep calls to equivalent methods using java.time types
- Types inheriting Object.toString() should not be assigned to string
parameter in logging statements.
* Break circular dependency between core and util
Created a new :common project and moved a minimum
number of classes to break the circular dependency
between the two projects. This gets rid of the
gradle lint dependency warnings.
Also separated api classes and testing helpers into
separate source sets in :common so that testing
classes may be restricted to test configurations.
