Messaging: Allow deletion of messages without a sim inserted

* Currently there is a check in place checking for the presence of a
  preferred sim card
* For deletion of a conversation and message this is unnecessary and
  deleting a conversation from the main view does also not have that check
  already, so replace the check with just checking for being the default
  messaging app

Fixes: https://gitlab.com/LineageOS/issues/android/-/issues/5974
Test: Try deleting a single message or conversation from within
 conversation before and after
Change-Id: Icd47882eb29e16a17ad57a79ea5e0c0f7855ffc6