Fixed screen brightness override in manual mode.

The screen brightness override would make itself persistent, to
communicate to the user her changes aren't taking place. However,
this caused a bug in manual brightness mode, because the setting
was never cleare, so it was removed.

Test: manual.

Change-Id: I187ed7a4691ba15284cf50adf8266ff161878c2a
Fixes: 78519580
1 file changed