Implement GNSS APIs for Automotive Power Management.

Automotive Suspend to RAM doesn't work when GNSS requests are
actively running. This change introduces system APIs for suspending
and resuming GNSS.

Bug: 187348886
CTS-Coverage-Bug: 203703449
Test: Presubmits
Change-Id: If25c761e8618bebaf989392afc0a676f930dfd78