camera2: Add HAL1 compatibility shim skeleton.

This adds basic support for running the Camera2 API on a device running
a camera HAL version lower than CAMERA_MODULE_API_VERSION_2_0.

This CL includes support for:
- N-way preview output streams
- N-way jpeg output streams
- CameraDevice emulation at the binder interface
- Basic camera metadata querying in the CameraManager

Bug: 15117269
Bug: 15116722

Change-Id: I8322955034c91f34bb348d4b28c2b774dbef38f6