Add .apt_generated to .gitignore

Change-Id: I874cfbcf96e463ef5f1e5a9650d52221895bea1d

.gitignore

diff --git a/.gitignore b/.gitignore
index b470f50..f47d0cd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+/.apt_generated
 /.classpath
 /.idea
 /.primary_build_tool