build: Switch to gradle build system

Change-Id: I0a11a49860a361684815dedd07e992d27d497523
diff --git a/.gitignore b/.gitignore
index 619d7e5..71af2c9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,4 +31,46 @@
 .settings
 
 # Netbeans specific project files
-nbactions.xml
\ No newline at end of file
+nbactions.xml
+
+# generated files
+bin/
+gen/
+out/
+obj/
+build/
+app/src/*/libs/
+app/src/*/obj/
+
+# Local configuration file (sdk path, etc)
+local.properties
+
+# Eclipse project files
+.classpath
+.project
+
+# OSX files
+.DS_Store
+
+# Windows thumbnail db
+Thumbs.db
+
+# IDEA/Android Studio project files, because
+# the project can be imported from settings.gradle
+.idea
+*.iml
+gradle
+
+# Old-style IDEA project files
+*.ipr
+*.iws
+
+# Gradle cache
+.gradle
+gradle.properties
+
+# Sandbox stuff
+_sandbox
+
+# Emacs stuff
+prj.el