Add fold state to voice call session am: 65debc1e am: 11d646ee am: 20cc16c2

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/opt/telephony/+/23214365



Change-Id: Id96a6ecd97d8b1d54ca7a5d29d4ffb98eea9d828
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>