Revert "Link to libsnapshot_cow where libsnapshot is linked." am: 300a8eb122 am: d46ed87737 am: 4d516c648f am: 8d270bd1c9

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/1447801

Change-Id: Iecff11741ab608c2b11d1426c1a3129293770c1e