build: remove custom rxjs imports rule in favor of import-banlist rule (#18157)

Author: devversion

tools/tslint-rules/rxjsImportsRule.ts

@@ -114,7 +114,6 @@
     "no-undecorated-class-with-ng-fields": true,
     "setters-after-getters": true,
     "ng-on-changes-property-access": true,
-    "rxjs-imports": true,
     "require-breaking-change-version": true,
     "class-list-signatures": true,
     "coercion-types": [true,
@@ -182,7 +181,9 @@
       ".*": "kebab-case"
     }],
     "no-unescaped-html-tag": true,
-    "import-blacklist": [true, ["^@schematics/angular/.*(ast).*"]]
+    // Ensures that all rxjs imports come only from `rxjs` and `rxjs/operators`. Also ensures
+    // that no AST utils from `@schematics/angular` are imported. These should be vendored.
+    "import-blacklist": [true, ["^@schematics/angular/.*(ast).*", "^rxjs(?!$|/operators$).*"]]
   },
   "linterOptions": {
     "exclude": [