Fix build failure for the proguard warnings on Mac OS. (#2395)
Fix build failure for the proguard warnings on Mac OS. (#2395)

Summary:
## Motivation (required)

The proguard warnings make the build failed in the Mac OS.

## Test Plan (required)

The request don't change the logic and doesn't need test.
Pull Request resolved: https://github.com/facebook/fresco/pull/2395

Reviewed By: defHLT

Differential Revision: D17498668

Pulled By: oprisnik

fbshipit-source-id: 4ec96484492c10920a63557d48913159257e647a

facebook/fresco,facebook/fresco,facebook/fresco,facebook/fresco,facebook/fresco,facebook/fresco