Allow for overlaying dynamic shared libraries

Overlays targeting shared libraries should be loaded into the
resources of every target that depends on the shared library.

Static shared libraries are currently not supported because overlays
should override all versions of static shared libraries and there is
not currently support for an overlay targeting multiple APKs.

Also created a test instrumentation and host test suite for testing
overlays and packages on the system image.

Bug: 140790224
Test: atest OverlayRemountedTest
Change-Id: I20a217b6368d6cf92b2b9f46908fd58012933f72