Merge "health AIDL: Add readme" am: 9af94c627c am: fe5ba8ae61 am: 1c4e695225 am: 60ff9fd511

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1875620

Change-Id: Ifb7a1b6b43a6575aa7f9626f8a2f4dad608972ec