BSN: Allow concurrent reads to consistency DB

Allow concurrent reads to the consistency DB since the
database lock the block was originally protecting against
is gone.

Closes-Bug: #1357102
Change-Id: I1618b4046e995c796757e723f99288e486683339
(cherry picked from commit b09c9950649c4c9fffa0b096eb21152cd84fe56f)
Merge "BSN: Allow concurrent reads to consistency DB" into stable/icehouse