build(aio): add API static members to search index (#21988)

Previously searching for `compose` did not include `Validators`
in the search results because we were not including all the
`static` members of API docs in the index.

PR Close #21988

aio/tools/transforms/angular-base-package/processors/generateKeywords.js

@@ -97,7 +97,7 @@ module.exports = function generateKeywordsProcessor(log, readFilesProcessor) {
 
           // Special case properties that contain content relating to "members"
           // of a doc that represents, say, a class or interface
-          if (key === 'methods' || key === 'properties' || key === 'events') {
+          if (key === 'members' || key === 'statics') {
             value.forEach(function(member) { extractWords(member.name, members, membersMap); });
           }
         });