Don't repeat template jsdoc tag

Error reported by the compiler:
```
ERR! compile closure/goog/array/array.js:1196: ERROR - Bad type annotation. @template tag at most once
ERR! compile  * @template K
ERR! compile               ^
ERR! compile 
ERR! compile 
ERR! compile 1 error(s), 0 warning(s)
ERR! compile 
ERR! Process exited with non-zero status, see log for more detail: 1 
```