usb: Rename the config to "charger" in charger mode init.usb.configfs.rc has the same trigger condition of midi function. Rename the config name to "charger" to avoid triggerring twice of the midi function. Bug: 188744218 Test: USB enumerated in charger mode Signed-off-by: Kyle Tso <kyletso@google.com> Change-Id: Ica112fb4be66356901f6d5f21b79b9e648d49f35