Create/Update assets for version 1.12.2

assets/minecraft/blockstates/frosted_ice.json

@@ -0,0 +1,8 @@
+{
+    "variants": {
+        "age=0": { "model": "frosted_ice_0" },
+        "age=1": { "model": "frosted_ice_1" },
+        "age=2": { "model": "frosted_ice_2" },
+        "age=3": { "model": "frosted_ice_3" }
+    }
+}