(This is a merge of http://go/wvgerrit/134316.)
This patch fixes code that would trigger -Wshorten-64-to-32 by
implicitly narrowing a variable from 64 to 32 bits. Most of the time, it
does this by making the implicit conversion explicit. Occasionally,
where it makes sense, it does this by expanding the code to operate on a
64-bit value.
This patch removes LicenseKeysTest::NumContentKeys(), which no one was
using, as all the tests access content_key_count_ directly.
Bug: 194971260
Test: x86-64
Change-Id: Iae7685c10b9db989253b349cab693728b438798d
c45559177a