[ImgBot] Optimize images

*Total -- 1,568.48kb -> 1,396.36kb (10.97%)

/android/imgs/notification-and-qs.png -- 558.78kb -> 457.84kb (18.07%)
/android/imgs/head-tracking-and-gestures.png -- 155.67kb -> 131.06kb (15.81%)
/linux/assets/pod3.png -- 854.02kb -> 807.46kb (5.45%)

Signed-off-by: ImgBotApp <ImgBotHelp@gmail.com>

Author: ImgBotApp