this change adds a set of library functions to facilitate
accessing(retrieving) configuration items.
Specifically, added template functions for accessing configuration
items for following types:
OptionalBool, OptionalInt32, OptionalUInt32, OptionalInt64,
OptionalUInt64, OptionalString
Design doc: go/design-confighal
Bug: 34724435
Test: build, run
Change-Id: Icca56d0d9e086b9d94c9b1168df041bf7d418698
This change adds configstore@1.0 HAL which provides static configuration values
to the framework. As a first attempt, a configuration item in the
surfaceflinger (VSYNC_EVENT_PHASE_OFFSET_NS) is choosen and converted to
a HAL function named vsyncEventPhaseoffsetNs().
Design doc: go/design-confighal
Bug: 34314793
Test: build & run. make sure that configstore is up and running.
$ ps -A | grep configstore
Change-Id: Ibc70b14176d2e0144a5745d71ceba49ebc3ca706
