Device do network scan after user rotates NetworkSelection page

To avoid to do oncreate when device is rotated or the screenSize
changed. Adding the activity's android:configChanges as
"orientation|keyboard|keyboardHidden|screenSize|screenLayout
|smallestScreenSize". (Based on SettingsHomepageActivity's settings
and the smallestScreenSize is for screensize changed on
different display.)

Bug: 204039043
Test: atest AutoSelectPreferenceControllerTest (pass)
atest OpenNetworkSelectPagePreferenceControllerTest (pass)
atest NetworkSelectSettingsTest (pass)

Change-Id: I6aa009fc52a85024a29bf48a3e7d1aadcab067d8