Merge "health AIDL: Add readme" am: 9af94c627c am: fe5ba8ae61 am: 1c4e695225 am: 60ff9fd511 am: 2af9b1b036

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

Change-Id: I92caefeef08350df8b9489553d676f5fb4c36ff1