Add .apt_generated to .gitignore

Change-Id: I0e253e8f503248d7bcae20bd389766ec83d32521
diff --git a/.gitignore b/.gitignore
index 8c58b98..ec6ea01 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,4 @@
 /buck-cache
 /buck-out
 *.iml
+/.apt_generated/