TokenManager: use full id in token

Previously, because of an error in the code that combined ids together,
only the bottom 15-bits of an id was used in the token (even though the
HMAC was computed from the full id). This meant that new tokens created
could invalidate previous tokens.

Bug: N/A
Test: (sanity) YouTube, (sanity) tokens always verified now (or error)
Change-Id: I493c76f77601cb1bfb74c6de81eb6a44f08d2ea3
2 files changed