Cleanup: Shift input shortcuts out of PWM

With new key gesture event handler APIs, different components
can define and reach to different shortcuts, so trying to shift
shortcut handling code to place that makes sense, instead of
putting it in PWM.

Bug: 358569822
Test: atest InputManagerServiceTests
Flag: EXEMPT pure refactor
Change-Id: I78c7f765bac7ec6a866730fdf3e94cf0a444569d