Setup fbjni sub-project for maven (#119)

Summary:
Set up our fbjni sub-project to be published to Maven Central.
This removes a bunch of abiFilters that we no longer make use of, too.
Closes https://github.com/facebook/Sonar/pull/119

Reviewed By: priteshrnandgaonkar

Differential Revision: D8694537

Pulled By: passy

fbshipit-source-id: de246fbda99c02856fbc7806b78df2114cb82acb

settings.gradle

@@ -21,8 +21,6 @@ include ':libevent'
 include ':openssl'
 include ':rsocket'
 
-
-
 project(':fbjni').projectDir = file('libs/fbjni')
 project(':easywsclient').projectDir = file('libs/easywsclient')
 project(':sonarcpp').projectDir = file('xplat')