Merge changes I335fb48f,Id5d98c7f,I9f66a5d1,Iee72576d,Id8ca634b into main

* changes:
  Introduce base class to hold uninstall stage related data
  Introduce UninstallRepository and UninstallViewModel
  Foundation of Uninstall flow in PiaV2
  Cache the staged session id to skip a staging again
  Replace if..else-if with a switch