Merge libdexfile_external into libdexfile.

To reduce the number of DSO's. libdexfile_external only adds a few
small functions on top of libdexfile, and it's still only those
functions that are available in the APEX stubs.

Also rename libdexfile_external_static to libdexfile_static, for
consistency.

Since libdexfile now has stubs, we need to add test_for properties to
avoid linking against the stubs in tests.

Test: Flash and boot with userdebug and eng to try both release and
  debug modules.
Test: art/build/apex/runtests.sh
Bug: 143978909
Change-Id: Ia011fa3a86509839ea0d80ad5fcad67ee5ce68d9
10 files changed