Merge "Fix the null toString logic." into udc-dev am: 217d64da am: 093c70d8 am: e466df0f am: f04fbedd

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23048862



Change-Id: Ie6bdd2b202491cb9691928034e1bd99bb4d111ef
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>