Tighten visibility in the -ListAdapter classes. am: 3bd1033da8

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/IntentResolver/+/20579956

Change-Id: Ie102c7985d320763ccfd0146060019f7592ac536
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>