[ Merge of http://go/wvgerrit/96071 ]
Changes to how the usage table method InvalidateEntry() behaves
required additional changes to CDM code that uses this method.
This involved some refactoring to AddEntry(), moving the LRU
related code to its own function.
A few unittests had to be changed / removed as the moving
multiple entries changes expectations of several existing tests.
Several additional helper methods have been created to improve
readability. These include getters for information about the
usage table, a method for releasing stale entries, and a method of
recording LRU metrics.
Bug: 150890014
Bug: 150887808
Bug: 154269671
Test: Linux unit tests and Android unit tests
Change-Id: I11a98f9a2dea9b2ae57b37d7d4483a37be721763