Camera VTS: Fix AIDL status typo

"physicalCameraDeviceStatusChange" returns a default
ScopedAStatus that will not include a valid AStatus instance.
This will result in binder instabilities once the status
is being parceled.
Return "ScopedAStatus::ok" instead.

Bug: 253993253
Test: adb shell VtsAidlHalCameraProvider_TargetTest
Change-Id: I219f608a04aaec0631e3de58a7e0d47a30294e52