Turn on eslint rule key-spacing and fix existing errors.

.eslintrc

 {
     "extends": "google",
     "plugins": ["html"],
     "rules": {
       "accessor-pairs": "off",
       "array-bracket-spacing": "off",
       "array-callback-return": "off",
       "arrow-parens": "off",
       "block-scoped-var": "off",
       "brace-style": "off",
       "camelcase": "off",
       "catapult-camelcase": ["error", {
         "properties": "never"
       }],
       "comma-dangle": "off",
       "comma-spacing": "off",
       "curly": "off",
       "default-case": "off",
       "dot-location": "off",
       "dot-notation": "off",
       "eqeqeq": "error",
       "generator-star-spacing": ["error", "after"],
       "guard-for-in": "off",
       "handle-callback-err": "off",
       "indent": "off",
-      "key-spacing": "off",
+      "key-spacing": "error",
       "keyword-spacing": "error",
       "max-len": ["error", {
         "ignorePattern": "((// @suppress longLineCheck)|:)$",
         "ignoreUrls": true
       }],
       "max-nested-callbacks": "off",
       "max-statements-per-line": "off",
       "new-cap": "off",
       "new-parens": "off",
       "no-alert": "off",
@@ skipping 50 matching lines @@
       "require-jsdoc": "off",
       "semi": "off",
       "semi-spacing": "off",
       "space-unary-ops": "off",
       "spaced-comment": "off",
       "valid-jsdoc": "off",
       "wrap-iife": "off",
       "yoda": "off"
     }
 }