Add header_namespace to handle cross-platform uses

Differential Revision: D7101683

fbshipit-source-id: 2a95cd1447d4cc5d796556e3281d08136cd130ff

ReactAndroid/src/main/jni/first-party/fbgloginit/BUCK

@@ -5,6 +5,7 @@ cxx_library(
     srcs = [
         "glog_init.cpp",
     ],
+    header_namespace = "",
     exported_headers = ["fb/glog_init.h"],
     compiler_flags = [
         "-fexceptions",