Update to latest revision of Echo schema

This patch updates Echo to revision 6081131 of Schema:Echo, adding a 'rev_id'
field and the code to populate it. The patch also increments the logging
version identifier to 1.5.

Bug: 46045
Change-Id: I4ac1a25c306b0e0983a3490a29fe3dc4aa4bfc6f
Merge "Update to latest revision of Echo schema"