Removing the initialising the mode with system pref mode.

This is unncessary because the initial active mode by system is the
correct mode, and there is no need to initialise with system pref mode.
But this mode needs to be set while clearing user pref mode.

Bug: 221400174
Test: atest DefaultDisplayModeTest
Test: atest LocalDisplayAdapterTest
Change-Id: Ic7533f1974cd9fe4f418d807929490e06ca1a274
(cherry picked from commit b14bca30)