Revert "sdm660-common: specify encryption format for adoptable storage"

This reverts commit 6f465205c3871d77b28eb844912b65b08937c9a3.

Reason for revert: This causes weirdness on adoptable storage devices
that didn't set XTS encryption on /data - files sometimes get corrupted,
so let's just fall back and use AES to match.

Change-Id: I5154e915ad97e772d3c0634b1ef29049b82b8d30

vendor.prop

@@ -2,9 +2,6 @@
 # vendor props for sdm660
 #
 
-# Adoptable Storage
-ro.crypto.volume.options=aes-256-xts
-
 # Audio
 af.fast_track_multiplier=1
 audio.deep_buffer.media=true