ASEC resize tweaking, allow read-write mounting.

ASEC resize tweaking, allow read-write mounting.

Resize is no-op when sector count is unchanged; the caller can't
anticipate how vold does its sector calculations.

After resizing, we need to mount the container read-write, so allow
the caller to request "ro" or "rw" mode.

Handle ENOTSUP when trying to fallocate() on some filesystems

Bug: 16514385
Change-Id: I0d3a378280d4c36d14f8108ff428102283d583fa