chore(lint): replace enforce-copyright-header rule with the native equivalent

tools/tslint/enforceCopyrightHeaderRule.ts

@@ -1,32 +0,0 @@
-import {RuleWalker} from 'tslint/lib/language/walker';
-import {RuleFailure} from 'tslint/lib/lint';
-import {AbstractRule} from 'tslint/lib/rules';
-import * as ts from 'typescript';
-
-export class Rule extends AbstractRule {
-  public static FAILURE_STRING = 'missing copyright header';
-
-  public apply(sourceFile: ts.SourceFile): RuleFailure[] {
-    const walker = new EnforceCopyrightHeaderWalker(sourceFile, this.getOptions());
-    return this.applyWithWalker(walker);
-  }
-}
-
-class EnforceCopyrightHeaderWalker extends RuleWalker {
-  private regex: RegExp = /\/\*[\s\S]*?Copyright Google Inc\.[\s\S]*?\*\//;
-
-  public visitSourceFile(node: ts.SourceFile) {
-    // check for a shebang
-    let text = node.getFullText();
-    let offset = 0;
-    if (text.indexOf('#!') === 0) {
-      offset = text.indexOf('\n') + 1;
-      text = text.substring(offset);
-    }
-    // look for the copyright header
-    let match = text.match(this.regex);
-    if (!match || match.index !== 0) {
-      this.addFailure(this.createFailure(offset, offset + 1, Rule.FAILURE_STRING));
-    }
-  }
-}

tslint.json

@@ -4,7 +4,7 @@
     "node_modules/vrsource-tslint-rules/rules"
   ],
   "rules": {
-    "enforce-copyright-header": true,
+    "file-header": [true, "Copyright Google Inc\\."],
     "no-duplicate-imports": true,
     "no-duplicate-variable": true,
     "no-jasmine-focus": true,