Avoid duplicate text on keyguard indication

It's possible that the transient indication will say "Charged" and the
power indication will be the same. In those cases they should not be on
top of each other.

Test: plug device, press power to wake-up
Fixes: 151181410
Change-Id: I15a6ab799a655ef84e7c8d5229b2d9cf4d8597fc