Allow healthd sys_tty_config

healthd performs privileged ioctls on the tty device
when in charger mode. Allow it.

This fixes a bug where off charging mode is forcing the device
to reboot into recovery.

Addresses the following denial:

type=1400 audit(15080631.900:4): avc:  denied  { sys_tty_config } for  pid=130 comm="healthd" capability=26  scontext=u:r:healthd:s0 tcontext=u:r:healthd:s0 tclass=capability

Bug: 13472365

(cherry picked from commit c8012152)

Change-Id: I701ad577c6814b0dafaef1367d0445b47a104f3c