Check for dexdump in compare_transform.sh
Check for dexdump in compare_transform.sh

Summary: Be more upfront about the dexdump dependency and avoid incorrect success when comparing APKs.

Reviewed By: int3, ssj933

Differential Revision: D17820763

fbshipit-source-id: 8ff7648283240dd1fae324e0e03fb023c339e265

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex