Game Driver: plumb driver choice and loading time to GpuStats

This change plumb the below info from GL and Vulkan loader:
1. Intended driver to use
2. Whether intended driver is loaded
3. Total driver loading time

Bug: 123529932
Test: Build, flash and boot. Verify the GpuService receiver side.
Change-Id: I967d4361bf0e04c02390c7555617575c19ecadd4