Migrate WindowContext#onConfigurationChanged to ClientTransaction (8/n)

1. Fix Binder.getCallingPid() check in
attachWindowContextToDisplayContent. Otherwise, Binder.getCallingPid()
will always be the MY_PID after Binder.clearCallingIdentity()
2. Remove unnecessary ownerUid in WindowContextListenerImpl.

Bug: 290876897
Test: atest WmTests:WindowContextListenerControllerTests
Change-Id: I6effd53a2b94d1c4e88514c93b853e3de07f8da3