Add function to test user messages query by timestamp

-Updates the user messages tests to test query users messages
 by timestamp.
-Updates the negative user messages tests to test query users
 messages with invalid time format.

Depends-On: I3d94bac4304c236f275abe7ce31432b0e2384247
Change-Id: I7a048c754cb703eebee709e35d379a4c51a80b3a
3 files changed