add scoped_trace_event to save TRACE_EVENT
fix bug: fetch new pref after call callback.
unittest save trace event.
scoped_trace_event add header guard.
add device_errors for check the last device error.
refactory property unittest, extract common env setup, div test.
trace value_map_device_property_store object change.
need clean error before set error.
name appropriate
add async_task and it's unittest
DeviceThreadMock use LazyInstance or the dtr order will lead to error.
add async_task_observer_mock to mock AsyncTaskObserver
impl property async set value
property Notify async task status with error code in param
unittest property async set value
unittest project depend on dynamic_annotations