[Java] Add bloom filter JNI bindings

Summary:
1. Add bloom filter JNI bindings
2. Unit-tests for bloom filters

make rocksdbjava
make sample

Reviewers: haobo, yhchiang, sdong, dhruba, rsumbaly, zzbennett, swapnilghike

Reviewed By: yhchiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18183