[automerger skipped] [DO NOT MERGE] Add android:relinquishTaskIdentity for multi-pane am: 917945d037 am: 89930efeb5 -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/16091757

Change-Id: Iae9a785f6a6c4165f7988ced03467f44527aff53