initial mediasanalytics framework

This encompasses the basic framework files for mediaanalytics.  This
includes the library code to run in clients, the interface definitions
to get to the service, and the mediaanalytics service.

This version of the patchset also incorporates a wholesale change from
"Media Statistics" to "Media Analytics" -- which involved both textual
changes and file renaming

This does not include the changes to other entities that will be sending
data. We'll do those under separate per-entity commits.

Bug: 30267133
Test: run through cts' media stress tests
Change-Id: Iee7e722d10fd57c5d6b14e2947117ed0d3af4f2a