Use APKPure App
Get Water Proof Test - Android wear an Sony xperia old version APK for Android
Testapparaat waterdicht vermogen.
The app uses the Barometer sensor to measure in-device pressure,
calculates it and recognise if it's water proof.
Just press the screen with a bit force (not too hard or too weak)
and you'll get the result.
Disclaimer:
This app is not intended to absolutely measure your device's water proof.
I take no responsibility for any water damage to your deveice.