Don't apply UI width limitation to an external display

config_maxUiWidth value is applied to all displays discovered
at the boot time, see
com.android.server.SystemServer::startOtherServices() calling
wm.displayReady()

It is correct for internal displays but sometimes the device can
boot with an external USB-C-to-HDMI connected display. In that case,
config_maxUiWidth is applied to that display as well, making
the image on the external display scaled  improperly.

From another point, this config value is not applied when the
external display is connected when the boot is finished, so
to make it consistent we should not apply that config to the
display connected before device boots as well.

By this change, we make sure that config_maxUiWidth is applied to
internal displays only.

Bug: 304339160
Test: connect the external display and reboot the device.
Signed-off-by: Aleksej Makarov <aleksej.makarov@sony.com>
Change-Id: I774f1987ed3c8504bb04dd072243edc498d14315