Use libcutils_headers for android_filesystem_config.h

android_filesystem_config.h is found since system/core/include is on
the include path for all projects and contains a symlink to the real
android_filesystem_config.h.  This is fragile and the below bug seeks
to remove this symlink and have users correctly depend on
libcutils_headers.

Bug: 165825252
Test: build
Change-Id: I1aad6a2e8fbe87635e97b0ac1be3414403353382
diff --git a/liblog/Android.bp b/liblog/Android.bp
index 6051ac7..9c1c463 100644
--- a/liblog/Android.bp
+++ b/liblog/Android.bp
@@ -97,6 +97,7 @@
 
     header_libs: [
         "libbase_headers",
+        "libcutils_headers",
         "liblog_headers",
     ],
     export_header_lib_headers: ["liblog_headers"],