[Polymetis] Tune gains for Kuka Iiwa Robot

## Type of Issue

Select the type of issue:
- [x] Bug report (to report a bug)
- [ ] Feature request (to request an additional feature)
- [ ] Tracker (I am just using this as a tracker)
- [ ] Refactor request
- [ ] Documentation Ask

## Description

Gains in kuka_sim.yaml should be tuned. Current setting exhibits drooping and slight oscillation behavior.

https://user-images.githubusercontent.com/12128112/175667789-24b17811-62f1-46d9-a836-18ddc620c37e.mov
Kuka iiwa with 1_set_ee_pose.py

## Current Behavior

Drooping and slight oscillation with current gain settings

## Expected Behavior

Achieving desired end position

## Steps to reproduce

Run `launch_robot.py robot_client=kuka_sim robot_model=kuka_iiwa use_real_time=false gui=true`
Navigate to examples folder and run `python 1_set_ee_pose.py `

## Links to any relevant pastes or documents

Attached video was run with the following settings:
default_Kq: [100., 150., 50., 75., 25., 10., 10.]
default_Kqd: [10., 20., 5., 10., 2.5, 1., 0.5]

These were sourced from [here](https://github.com/fair-robotics/polymetis/blob/d63bc5d6f2129a6d0739a56221762f0b15d7e8bd/fair-robot-envs/hydra_plugins/fair_robot_envs_hydra_plugin/conf/env/pybullet_kuka_box_table.yaml#L39)