This allows flame to boot TWRP. Still will need to work on
super partition for vendor and system access.
The plan will be to cherry-pick any updates to android-9.0
through gerrit.twrp.me to this branch as a WIP.
Therefore InstallPackage() doesn't need to worry about the details of a
given Package.
Bug: 127071893
Test: run update from /bin/recovery --update_package=@path, sideload a package
Change-Id: I0caa36785b43924f884ee398e7ea640d7472a92e
Build libinstall as a shared library. Also drop the dependency on the
global variables in common.h.
Test: unit tests pass, sideload an OTA
Change-Id: I30a20047768ce00689fc0e7851c1c5d712a365a0
