Retrieving device properties (equivalent to executing getprop on the device) can be done using the requests below.

Get all device properties

This requests retrieves all properties and create a Map of String -> String to allow working with properties like this properties["sys.boot_completed"].

val properties: Map<String, String> = adb.execute(
    request = GetPropRequest(),
    serial = "emulator-5554" 
)

Get single device property

If only a single property is needed then you can use the shorter version:

val value: String = adb.execute(
    request = GetSinglePropRequest(name = "sys.boot_completed"),
    serial = "emulator-5554" 
)