Remove finalized concept from media.metrics

the 'finalized' concept didn't pan out -- remove references to it. Purged some
uses of generateSessionID().  Simplifies the code flow.

Bug: 71874686
Test: logcat/dumpsys

libwvdrmengine/cdm/src/ami_adapter.cpp

@@ -18,7 +18,6 @@ AmiAdapter::AmiAdapter(int64_t parent) :
 }
 
 AmiAdapter::~AmiAdapter() {
-  analytics_item_.setFinalized(true);
   analytics_item_.selfrecord();
 }