Add simFingerDown, simFingerUp, onUiReady to UdfpsShell

adb shell cmd statusbar udfps simFingerDown
  - Simulates onFingerDown within sensor in UdfpsController
adb shell cmd statusbar udfps simFingerUp
  - Simulates onFingerUp within sensor in UdfpsController
adb shell cmd statusbar udfps onUiReady
  - Runs onUiReady on AlternateTouchProvider

Bug: 250710937
Test: Manual testing
Change-Id: I1bec8aab5614c0b53e62324bd3fd608062b0badd