Update GpuStats/SFStats for puller API feedback

Update gpustats and surfaceflinger for statsd native puller API
feedback.

Test: make
Test: atest libsurfaceflinger_unittest
Test: atest gpuservice_unittest
Bug: 150788562
Change-Id: I1ba09b0c06ec7fb50dfd2b63ed0291a54e69d917
4 files changed