Fix the shared library extension on Apple platforms
Fix the shared library extension on Apple platforms

We were generating .so files, but expect the outputs to be .dylib
(in places where we dlopen, etc.). Further, the file-type of the
libraries was actually DYLIB, not BUNDLE.

This fixes an issue with ANGLE-on-Mac, where we couldn't find libEGL,
and that (in turn) couldn't find libGLESv2.

Bug: skia:13040
Change-Id: I5eb212b9f19698cf0e0459df8ba70e62e87f5a4c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/534558
Reviewed-by: Ben Wagner <53965154ffeecc4a10886eab9259e95965f2979a@google.com>
Commit-Queue: Brian Osman <794c0b5534edf5601d88e1d41975d0262da12894@google.com>

google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia