Add libjsonpbparse.

- libjsonpbparse is intended to be used in client parsing code,
  but due to libprotobuf versions it can't be used yet. Hence,
  libprocessgroup continue to use libjsoncpp.

Test: builds
Bug: 123664216
Change-Id: I01b08a0e6ba1110f2f3398ddde9333622153dc9a
5 files changed