Fix the UI updatestate issue

There are two issues:
1. when user enters this page first time, the
settings does not do updatestate.
2. The UI status failed to update after quickly switching from the mobile network settings to the Wi-Fi calling page and back. This caused the UI to be displayed even when isVisible was false.

do updatestate and update the getAvailabilityStatus

Bug: 405378152
Test: atest VideoCallingPreferenceControllerTest
Flag: EXEMPT bugfix
Change-Id: I178d3719e527c889297a187f5baf3ffecc4cc6cc