Fix android compatibility

[okhowang]

1. langinfo
   <langinfo.h> is included by nl_langinfo which is used in condition.
   so I just sync this condition with headers. because some old ndk(r13) has no <langinfo.h>
2. statfs
   according to https://stackoverflow.com/questions/8275203/compiling-a-subset-of-boost-libraries-for-android-ndk, android platform can use <vfs.h> instead of <statfs.h> immediately.
3. utimensat
   api level < 12 has no utimensat function. see https://android-review.googlesource.com/c/platform/development/+/69602, and https://stackoverflow.com/questions/19374749/how-to-work-around-absence-of-futimes-in-android-ndk.
   so I use syscall instead. And define UTIME_OMIT if it's not defined

[gulrak]

Thank you for the PR!