Add a build.gradle file for gradle-based projects.

Change-Id: I20378cc4c5148a914bd8bc34eabb46c30043352f
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..f6a1fea
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,11 @@
+apply plugin: 'java'
+
+sourceSets {
+    main {
+        java.srcDirs = ['shared/src/main/java', 'applier/src/main/java']
+    }
+    test {
+        java.srcDirs = ['shared/src/test/java', 'applier/src/test/java']
+    }
+}
+