Refactor DoubleTapPowerPreferenceController

DoubleTapPreferenceController was previously used as the controller for
the "Quickly open camera" entry in the "System > Gestures"  screen and as the controller for
the toggle in the ["System > Gestures > Quickly open camera" screen.

This CL separates the DoubleTapPowerPreferenceController into two new
controllers to handle each case:
- Double Tap Power Preference Controller to control the "Quickly open camera" entry
- Double Tap Power To Open Camera Preference Controller to control the
  gesture's enable/disable toggle.

Android Settings Feature Request: b/380287172

Bug: 381499912
Test: atest DoubleTapPowerPreferenceControllerTest
Test: atest DoubleTapPowerToOpenCameraPreferenceControllerTest
FLAG: android.service.quickaccesswallet.launch_wallet_option_on_power_double_tap
Change-Id: I73fc7d97e1e330163858a60a4ba9a63bd9b5574f