Client update needed to match WebSocket spec changes

[client-library-maintainer]

A diff between this client library's spec and our hosted spec was found. The client may need an update to match any changes in our API. See the diff below:

--- https://raw.githubusercontent.com/polygon-io/client-jvm/master/.polygon/websocket.json
+++ https://api.polygon.io/specs/websocket.json
@@ -1995,7 +1995,7 @@
     "/indices/AM": {
       "get": {
         "summary": "Aggregates (Per Minute)",
-        "description": "Stream real-time minute aggregates for a given index.\n",
+        "description": "Stream real-time minute aggregates for a given index ticker symbol.\n",
         "parameters": [
           {
             "name": "ticker",
@@ -2004,7 +2004,7 @@
             "required": true,
             "schema": {
               "type": "string",
-              "pattern": "/^([a-zA-Z]+)$/"
+              "pattern": "/^(I:[a-zA-Z0-9]+)$/"
             },
             "example": "*"
           }
@@ -3552,6 +3552,131 @@
       "CryptoReceivedTimestamp": {
         "type": "integer",
         "description": "The timestamp that the tick was received by Polygon."
+      },
+      "IndicesBaseAggregateEvent": {
+        "type": "object",
+        "properties": {
+          "ev": {
+            "description": "The event type."
+          },
+          "sym": {
+            "type": "string",
+            "description": "The symbol representing the given index."
+          },
+          "op": {
+            "type": "number",
+            "format": "double",
+            "description": "Today's official opening value."
+          },
+          "o": {
+            "type": "number",
+            "format": "double",
+            "description": "The opening index value for this aggregate window."
+          },
+          "c": {
+            "type": "number",
+            "format": "double",
+            "description": "The closing index value for this aggregate window."
+          },
+          "h": {
+            "type": "number",
+            "format": "double",
+            "description": "The highest index value for this aggregate window."
+          },
+          "l": {
+            "type": "number",
+            "format": "double",
+            "description": "The lowest index value for this aggregate window."
+          },
+          "s": {
+            "type": "integer",
+            "description": "The timestamp of the starting index for this aggregate window in Unix Milliseconds."
+          },
+          "e": {
+            "type": "integer",
+            "description": "The timestamp of the ending index for this aggregate window in Unix Milliseconds."
+          }
+        }
+      },
+      "IndicesMinuteAggregateEvent": {
+        "allOf": [
+          {
+            "type": "object",
+            "properties": {
+              "ev": {
+                "description": "The event type."
+              },
+              "sym": {
+                "type": "string",
+                "description": "The symbol representing the given index."
+              },
+              "op": {
+                "type": "number",
+                "format": "double",
+                "description": "Today's official opening value."
+              },
+              "o": {
+                "type": "number",
+                "format": "double",
+                "description": "The opening index value for this aggregate window."
+              },
+              "c": {
+                "type": "number",
+                "format": "double",
+                "description": "The closing index value for this aggregate window."
+              },
+              "h": {
+                "type": "number",
+                "format": "double",
+                "description": "The highest index value for this aggregate window."
+              },
+              "l": {
+                "type": "number",
+                "format": "double",
+                "description": "The lowest index value for this aggregate window."
+              },
+              "s": {
+                "type": "integer",
+                "description": "The timestamp of the starting index for this aggregate window in Unix Milliseconds."
+              },
+              "e": {
+                "type": "integer",
+                "description": "The timestamp of the ending index for this aggregate window in Unix Milliseconds."
+              }
+            }
+          },
+          {
+            "properties": {
+              "ev": {
+                "enum": [
+                  "AM"
+                ],
+                "description": "The event type."
+              }
+            }
+          }
+        ]
+      },
+      "IndicesValueEvent": {
+        "type": "object",
+        "properties": {
+          "ev": {
+            "type": "string",
+            "enum": [
+              "V"
+            ],
+            "description": "The event type."
+          },
+          "val": {
+            "description": "The value of the index."
+          },
+          "T": {
+            "description": "The assigned ticker of the index."
+          },
+          "t": {
+            "description": "The Timestamp in Unix MS."
+          }
+        }
       }
     },
     "parameters": {
@@ -3609,7 +3734,29 @@
           "pattern": "/^(?<from>([A-Z]*)-(?<to>[A-Z]{3}))$/"
         },
         "example": "*"
+      },
+      "IndicesIndexParam": {
+        "name": "ticker",
+        "in": "query",
+        "description": "Specify an index ticker using \"I:\" prefix or use * to subscribe to all index tickers.\nYou can also use a comma separated list to subscribe to multiple index tickers.\nYou can retrieve available index tickers from our [Index Tickers API](https://polygon.io/docs/indices/get_v3_reference_tickers).\n",
+        "required": true,
+        "schema": {
+          "type": "string",
+          "pattern": "/^(I:[a-zA-Z0-9]+)$/"
+        },
+        "example": "*"
+      },
+      "IndicesIndexParamWithoutWildcard": {
+        "name": "ticker",
+        "in": "query",
+        "description": "Specify an index ticker using \"I:\" prefix or use * to subscribe to all index tickers.\nYou can also use a comma separated list to subscribe to multiple index tickers.\nYou can retrieve available index tickers from our [Index Tickers API](https://polygon.io/docs/indices/get_v3_reference_tickers).\n",
+        "required": true,
+        "schema": {
+          "type": "string",
+          "pattern": "/^(I:[a-zA-Z0-9]+)$/"
+        },
+        "example": "I:SPX"
       }
     }
   }
-}
\ No newline at end of file
+}