Enforce specifying sdk/private for apps.

All apps in master comply with this now, but new offenders
are being added daily. This will ensure compliance going
forward.

Test: vendor/google/build/build_test.bash --dist
Bug: 73535841

Exempt-From-Owner-Approval: reviewed in master/aosp, but this blocks aosp
Change-Id: Id3fbb502d26d91b64480fec74e241ba77fa0faff
Merged-In: Id3fbb502d26d91b64480fec74e241ba77fa0faff