Rename .include files to .inc

Change-Id: Ie7a59d598a5916d8620cb55064a1204f90bc148d
Reviewed-on: https://skia-review.googlesource.com/99244
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
8 files changed