tree b64fa1d73e9db5ca884170ff8c2ebd627f0e0012
parent 8acde7e93168f176f5e5f409be22c534a0b3d890
author Connor O'Brien <connoro@google.com> 1580527439 -0800
committer Connor O'Brien <connoro@google.com> 1580527685 -0800

time_in_state: track last update time per UID

This allows for optimizing reading this data by skipping UIDs that
have not been updated recently.

Bug: 138317993
Test: builds; libtimeinstate_test passes
Change-Id: Ic535d15d09dae274e47050f28a483c7d22b6ca04
Signed-off-by: Connor O'Brien <connoro@google.com>