Fix libfbjni compilation (#927)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/927

When D16220924 brought a new fbjni copy (with new directories), we forgot to fix the cmake files which are used by gradle build system.

Reviewed By: SidharthGuglani

Differential Revision: D17367160

fbshipit-source-id: 3e7d20d4c53ff3012a164bf6e32f1000ecb3ffc2

lib/fb/src/main/cpp/CMakeLists.txt

@@ -20,6 +20,7 @@ add_compile_options(
 file(GLOB fb_SRC
     *.cpp
     jni/*.cpp
+    jni/detail/*.cpp
     lyra/*.cpp)
 
 add_library(fb SHARED