Update gitignore to suppress Intellij and Gradle temp files.

Test: None
Change-Id: I276ca62f8965a82303be98fb6ea2f0a7a8e89c59
diff --git a/.gitignore b/.gitignore
index 3770f89..79d252b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
 build
 .classpath
+.gradle
 .project
 .settings
+*.iml