installer: Clean up ext-dependency jQuery code

installer: Clean up ext-dependency jQuery code

Follows-up c8833d8e8ecc.

* Select the input elements by class to avoid accidentally trigging
  on unrelated elements elsewhere on the page in the future, given
  the generic selector.

* Use on('change') instead of deprecated change() alias.

* Set properties directly instead of via prop() indirection.
* Get attribute directly instead of via data() indirection.

Change-Id: I5158aa26b5fd7327d6795f0a31bbffbe99043fbf