command to get current volume level
Use command adb shell dumpsys audio. It will list all the volume related information. e.g for alarm volume look for STREAM_ALARM in output logs.

- STREAM_ALARM:
    Muted: false
    Min: 0
    Max: 7
    Current: 2 (speaker): 7, 40000000 (default): 6
    Devices: speaker