API: Suppress existing NullableCollections lints am: 6a6aa5e23d am: 4da67dd2f6

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1566096

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I931b4ec091173789f480ecc761044a27944c4b85