Revert these to see if it fixes preview freezes

Revert "fix zsl mode for htc devices"

This reverts commit ca525f77f14b28d9b1021fdbeb2f70457b6a48d4.

Revert "fix zsl mode for m7"

This reverts commit 0ee4b729f655bd0c5d7efcf2923461b3b974a109.