RSDK-3534 Add last_reconfigured to each resource status

[benjirewis]

RSDK-3534

Updates rust protos (ran make buf). Updates GetReadingRe* use statements. Adds build_time field to LocalRobot derived from gRPC get_config header. Converts build_time to proto and adds that proto to every resource status as last_reconfigured.

Spoke with @gvaradarajan offline. We've added LastReconfigured timestamps to all resources for users of resources to have a better sense of when the resource was last constructed/updated in the backend. The micro RDK has no concept of "reconfiguration" or dynamic updates to resources, so we can just use the time at which we got the cloud config as the build_time for all resources. Note that build_time does not exist for non-cloud LocalRobots, so they'll return None as the last_reconfigured value.

[gvaradarajan]

LGTM