Fix several mainline media modules using system libraries

Several places in the media module (around extractors) were using
system-side libstagefright_foundation functions to access data passed
across the module boundaries; restructure libstagefright_foundation
so it works appropriately.

Bug: 193017338
Test: atest android.media.cts.MediaExtractorTest S-on-S, S-on-Q
Test: atest ColorUtilsTest
Test: atest ExtractorUnitTest
Change-Id: I7f8ab13905e31754b1a5ec2de97bc7ec242827ba