Rename gpu_mem.o to gpuMem.o am: 440cf722a9 am: 15748e0a12 am: 82aa83d22e

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

Change-Id: I5569aae4c5dd24f7566a5b6fe49cdc57763bc159
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>