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: I166d55111435762f099503db83c1a658f78e98e9