Game Driver: Add a Settings.Global property for sphal libraries

This change add the GAME_DRIVER_SPHAL_LIBRARIES property to save the
list of sphal libraries assessible to Game Driver.

Bug: 124448366
Test: Build, flash and boot.
Change-Id: I7cb06df80f19d87f5fd13d7df3c991ceb5bdfb06
Merged-In: I7cb06df80f19d87f5fd13d7df3c991ceb5bdfb06
Exempt-From-Owner-Approval: Change in CoreSettingsObserver.java is too
minor
5 files changed