Revert "Link to libsnapshot_cow everywhere libsnapshot is linked."

Revert submission 1433573-vab-libsnapshot-linkage

Reason for revert: b/169981170, update crash for droidfooders.
Reverted Changes:
Ie75bba98c:Link to libsnapshot_cow where libsnapshot is linke...
Ieedfadc55:libsnapshot: Partially implement OpenSnapshotWrite...
I28a5d4a88:Link to libsnapshot_cow everywhere libsnapshot is ...

Change-Id: I8c774ca4a8dec21dd308694bb8205861a19c3e12