Check mode/boost index before accessing cached support value am: 20b47da57a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13164079

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I1ae040e4c0f27d45a9eba4b9f06a50ab194d8d27