Use protoc-gen-javalite for java lite protos

Protobuf 3.5.2 does not natively support lite protos, instead they
are generated by the protoc-gen-javalite plugin compiled from
external/protobuf-javalite.

Bug: 117607748
Test: m checkbuild
Change-Id: I95c2d873f19d4c00e9dc312d7fdbe98cae250a8b