Update ConnectivityCheckTargetPreparer references

Use the new ConnectivityTestTargetPreparer name instead, as the preparer
is being made more generic.

Bug: 263665773
Test: m
Ignore-AOSP-First: In a topic with internal-only repo. Will cherry-pick
                   to AOSP immediately afterwards.
Change-Id: I520e92c449f366c51cda2f8b33fe9a354a8c0445
3 files changed