Rename fbjni shared library name to the standard soname

Summary:
Before we can upgrade to latest fbjni, we need to make sure our shared libraries are named the same.

Currently when we compile libfbjni it is named as `liblib_fb_fbjni.so`, where as the regular fbjni is expected to be named as `libfbjni.so`

Reviewed By: davidaurelio

Differential Revision: D16250801

fbshipit-source-id: 9a7f0f803d7e525985b40a49edcc0e660e9025f5

lib/fb/BUCK

@@ -35,6 +35,7 @@ yoga_cxx_library(
         "-std=c++11",
     ],
     platforms = (ANDROID,),
+    soname = "libfbjni.$(ext)",
     visibility = ["PUBLIC"],
     deps = [
         ":ndklog",