health: vendor.charger-* -> vendor.charger.

Devices may have actions triggered by
init.svc.vendor.charger. If the name is changed,
these actions are not triggered properly.

The name is usually vendor.charger, so the default
service will also use vendor.charger as the name.

Test: none
Bug: 215152892
Change-Id: Icb296ae82a6f3472730fdb3abc35dcede22889e7