Teach PinnerService to pin parts of APKs

This change teaches PinnerService how to pin parts of APK files, with
the specific regions of interest described by a small metadata file in
the APK root directory. Apksig has been modified to annotate signed APKs
with pinning metadata.

This CL also fixes a few resource management bugs and enhances the
dumpsys output.

Test: built dummy camera app, pinned stuff, verified log output
Change-Id: If72709ad2c0f2ec748f547a48a289473e4c60bab
Bug: 65316207