Fix some nits or typos found by chance

Change-Id: I42b9b3e377f01ff9612768f76c7d05fc5e379f0a
Clean event method difinition in meter storage base

For the event feature has dedicated storage implementation, clean the
event related definition in metering storage base.

Change-Id: I86003874232c57ae4982234de1a694159c1bd888
Merge "Fix some nits or typos found by chance"