Rename gpu_mem.o to gpuMem.o am: 440cf722a9

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2146977

Change-Id: Ie03fd704d632db7876bbdccb43de3005300347d4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>