If there are file-level enums, it still will generate what would have
otherwise been the outer class to hold them, since enums don't get
their own class in the streaming proto scheme.
Make the proto apis not @TestApi for now -- there's too much churn.
Test: make
Change-Id: I01fb7dca935261775efe2573ee009df4d0b07fd0
The classes there add a way for the platform to write out
protocol buffers that doesn't require lots of small objects,
generate code, and extra copying.
Includes the plugin for protoc to generate the constants.
Test: proto cts tests
Change-Id: I6385c198cecda9ac6fa533151609e3ace341af01
