Stop NaN being passed to brightness curve.

PowerManager.BRIGHTNESS_INVALID_FLOAT was being passed on when it shoudln't have been, if statement has been fixed to avoid this.

Bug: 152685837

Test: AutomaticBrightnessControllerTest, adb shell dumpsys display |
grep mBrightnessSpline (check no NaN values)

Change-Id: Ic2d22938ccc81cb2b9e2645b7e21acd89163b107
1 file changed