Merge "Update Java doc for FLAG_ACTIVITY_LAUNCH_ADJACENT" into rvc-dev am: 8411d737 am: a4c19e96 am: f30082d4 am: f510ff4d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11905502

Change-Id: Iff3f525b82eb0de1c10b8ae65043f0e6da65b729