Revert "Add NTFS support in vold"

This reverts commit 564f6c64.

Reason for revert: Un-backporting.

Note: This is not a direct revert. We should keep the minor refactoring
in PublicVolume.cpp; no point making the code worse.

Test: Revert.
Change-Id: Ic03ed25ad15a2da974921542a20cd27224347f68