ArrayUtils: rename concatElements() to concat() am: 96abd9452d

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2429552

Change-Id: I40242554249df84807bbd0ff54732d7701b4b6be
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>