API: Suppress existing NullableCollections lints am: 515b26ae98

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I2d47151b7e26e82706f2d94a13c4067fe71fc168
tree: 2e48d31cf7a87d9c5c302ccb94d495ba86c6048d
  1. framework/
  2. service/
  3. OWNERS