Ignore .gradle directores.

Test: git status

Change-Id: I3ce186e943e92fe78112bca7b600791b40e6aece
diff --git a/.gitignore b/.gitignore
index 2beb2f2..b093c81 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@
 gen/
 .vscode/
 *.code-workspace
+.gradle/