Clean up bugreport API.

Make BugreportManager class final.

Add FloatRange annotation for BugreportManager.onProgress() function's
parameter.

Make @IntDef in BugreportMode hidden.

Bug: 126434607
Test: builds
Change-Id: I95f004106ba97bc9e99859a8b23b96a86b6a43f4
3 files changed