Barcode Plugin uses Deprecated Camera API

[bhariharan]

Looks like the plugin is built on the Camera API, which was deprecated in API 21, which also happens to be our minimum supported version. We should build the plugin on the newer Camera2 API per Google's recommendation. API 21 is more than 6 years old at this point, and the old API could be removed at any point. I wouldn't want to ship with an API that has been deprecated for this long. I'd prefer to ship with the newer equivalent API, i.e. Camera2.

[bhariharan]

This work is complete.