Generate Android build targets for dm and nanobench

Generate targets for dm and nanobench from ninja and add them to the
generated Android.bp file.

Remove nanobenchAndroid and SkAndroidSDKCanvas. These rely on HWUI
internals and are currently unused.

Update gyp file references to removed files, just in case.

Change-Id: Ic6ae18a70bfd0c33804e7996d077f2081dfdfe07
Merged-In: Ic6ae18a70bfd0c33804e7996d077f2081dfdfe07
Reviewed-on: https://skia-review.googlesource.com/7635
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Leon Scroggins <scroggo@google.com>
(cherry picked from commit 6ccd2cabaac810edccab620d8a944f64b0432d44)
7 files changed