Standardize unpack_userparam.

Bug=26472080

Raise exceptions instead of return True/False.
Update all related scripts to use the new convention.

Change-Id: I7d8486bfcbc2a304c300e01c248550b5d6bf1e4a
12 files changed
tree: 12d7e48fcfa4bdf66d6a5fbe886067c5d8d5dc57
  1. acts/