Serialize structured data, currently using protocol buffers
Replaced the field localTimestamp of type STRING with a field localDateTime with type DATETIME for easier analysis in BigQuery. Changing back to proto3, intend to solve the defaults in protobufutils instead.
Changed to proto2 to support values that are the same as defaults in proto3, eg. 0 for int.
Changed the field naming to camel case in measurementprotocol proto
Generate java files by running: protoc -I=./proto --java_out=./src/main/java/ ./proto/*.proto