Revert "Initialize UserTracker with boot user"

This reverts commit a4d7fbc48cbaa57498066db4599a95dbbbb31183.

Reason for revert: Droidmonitor created revert due to b/362767795

Change-Id: Ia3dfaa463405b52a60d3ee2d72f1aae19409a2f9
3 files changed