Address API feedback and CTS on cloud devices

- Add additional javadoc for vendor and product ids
- Enumerate full allowed key code set for VirtualKeyEvent
- On cloud devices, CTS fails with 'bad address' for VirtualTouchscreen.
  Pass by address rather than by value to solve.

Bug: 216554655
Test: atest CtsHardwareTestCases:android.hardware.input.cts.tests
Change-Id: Ifb233d2b6c4eee1ffdcba218ed17312e67bac6f6