Generate protobufjs static module

- Rename root.js -> json.js and types.d.ts -> static.d.ts
  for clarity (match protobufjs' terminology)
- Generate static.js as well. Needed to access values of proto constants at runtime.
  E.g. android.surfaceflinger.HwcCompositionType.DEVICE.

Bug: 318503129
Test: npm run test:presubmit
Change-Id: Iaac2099d04c33413339ccdd82093cae0ce7eaf85