Put wired charging ripple back.

It was removed as a collateral damage of dead code cleanup (ag/15312956)..
Also made callback registeration more explicit.

Bug: 215568460
Test: atest frameworks/base/packages/SystemUI/tests/src/com/android/systemui/statusbar/charging/WiredChargingRippleControllerTest.kt
Test: adb shell cmd statusbar charging-ripple
Test: Plugging and unplugging phone
Change-Id: I2953c0f294b68b3c65515642f45e2b29d44449d1