Require targetSdkVersion>=O for updated graphics driver packages

In O, graphics drivers are loaded into a new restricted linker
namespace. Drivers built for previous versions of the OS may not work
under those restrictions, so require an updated driver package to
declare compatibility by setting targetSdkVersion >= O.

Bug: 34228255
Test: manually construct packages with and without
      targetSdkVersion >= O, confirm driver is used/not-used as
      expected.
Change-Id: I4518360433a6de5c6e1e792a6eedddf8c6bf4394