Allow fstatfs64 syscall for mediacodec/extractor

This syscall is used by the linker to detect files located on tmpfs

Bug: http://b/37245203
Bug: http://b/37590327
Test: boot an angler and check that mediacodec does not crash
Change-Id: I7147063db7d6b8ec39a25d39b60e8e6882addf6e