fix required in some places (#360)

Author: aleksandr-gringauz

schemas/rum/_view-properties.json

@@ -209,6 +209,7 @@
         "crash": {
           "type": "object",
           "description": "Properties of the crashes of the view",
+          "required": ["count"],
           "properties": {
             "count": {
               "type": "integer",
@@ -222,6 +223,7 @@
         "long_task": {
           "type": "object",
           "description": "Properties of the long tasks of the view",
+          "required": ["count"],
           "properties": {
             "count": {
               "type": "integer",
@@ -235,6 +237,7 @@
         "frozen_frame": {
           "type": "object",
           "description": "Properties of the frozen frames of the view",
+          "required": ["count"],
           "properties": {
             "count": {
               "type": "integer",