Game Driver Metrics: make gpu stats info parcelable

This change also rename the GpuStats*Atom to GpuStats*Info because we'd
like to make GpuStats generic to all the authorized recipients, but atom
is too specific to statsd.

Bug: 126560138
Test: adb shell dumpsys gpu --gpustats
Change-Id: Ie071277ae849a32607979d07aca7682febaf4368