Bug: b/121214641
Merge of http://go/wvgerrit/70768
Tests: usage_table_header_unittests (with and without hardcoded values)
DeleteEntry fails if the last entry is in use, since it cannot shrink
the table any further via swapping. The LoadEntry_LoadUsageEntry...
tests test to see that after deleting an entry x amount of times, the
usage table can load an entry. If the entry we want to load is within x
positions of the last entry of the usage table, the method cannot
succeed for the aforementioned reason.
Change-Id: Iccdaf538cb4bcbd34855f36c71aceaeb93b4a770