Deprecate the old rebootAndApply API

This API isn't aware of slot switch, and shouldn't be used by
phonesky. So we prefer to deprecate it in case new callers use
it accidentally. Also don't allow callers with REBOOT permission
to call it.

Bug: 170664917
Test: build
Change-Id: I540b87fad461cb2c900f3e9d177bb5147abc1a22