Revert "Add multi-user support for AutoTileManager"

This reverts commit 29d65f5e.

Reason for revert: Droidcop-triggered revert due to breakage https://android-build.googleplex.com/builds/quarterdeck?testMethod=testChangeUserCallbacksStoppedAndStarted&testClass=com.android.systemui.statusbar.phone.AutoTileManagerTest&atpConfigName=apct%2Fsystem_ui%2Funit_test-cloud-tf&testModule=&fkbb=6585473&lkbb=6585683&lkgb=0&testResults=true&badBuildCount=8&branch=git_rvc-dev-plus-aosp&target=aosp_cf_x86_phone-userdebug, bug b/158866689

Bug: 158866689
Bug: 154607890
Change-Id: Ia928824c17edf66675cc448cdcef305530e74010
Merged-In: I518334cca0a0960e0b3b74b43ac9fce4610c7bd0