Striders have 15 health

Striders have 15 health in Bedrock edition, while 20 in Java edition.

This can be fixed in the strider.json, if the value and max is set to 20.

"minecraft:health": {
        "value": 15,
        "max": 15
}

"minecraft:health": {
        "value": 15,
        "max": 15
}