Revert "redbull: update BOARD_API_LEVEL to T" am: ecd9d22132 am: a75a26cf77

Original change: https://googleplex-android-review.googlesource.com/c/device/google/redbull/+/22788402

Change-Id: Idd2dd86ff333ab6f7664fae3cf05f6b9d3de4088
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>