Update activeMode when it changes from SF

Update activeMode when after hotplug it has changed
and the change was not requested from display manager. This
happens when the mode has changed from the display device.
This is similar to what we currently do when the list of
supported modes has changed after hotplug.

Bug: 170298716
Test: atest LocalDisplayAdapterTest
Change-Id: I78d89fe85ae50ae3d6b1d0d60214f5b91f2e3ed7