message: fix(ivy): remove spurious comma in ngtsc-built .d.ts files
  On accident a comma was emitted between imports when generating .d.ts
  files. This commit removes it.
  PR Close
diff: @@ -59,7 +59,7 @@ export class DtsFileTransformer {
  const imports = this.imports.getAllImports(tsPath, this.coreImportsFrom);
  if (imports.length !== 0) {
  - dts = imports.map(i => `import * as ${i.as} from '${i.name}';\n`).join() + dts;
  + dts = imports.map(i => `import * as ${i.as} from '${i.name}';\n`).join('') + dts;
  }
  return dts;
  