Add gradle build files.

Change-Id: I62a8a31d4e6170ae6a71a1e03354aca7cee77766

.gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c8c70f2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/build
+/.gradle

build.gradle

diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..4aa8739
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,2 @@
+apply plugin: 'java'
+