Added universal gitignore file to facilitate clean sample repos

Change-Id: I0c00dbe8855ce2cc1efba9e015a93271c70c3207
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2dd1573
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,39 @@
+# built application files
+*.apk
+*.ap_
+
+# files for the dex VM
+*.dex
+
+# Java class files
+*.class
+
+# generated files
+bin/
+out/
+gen/
+
+# Libraries used by the app
+# Can explicitly add if we want, but shouldn't do so blindly.  Licenses, bloat, etc.
+/libs
+
+
+# Build stuff (auto-generated by android update project ...)
+build.xml
+ant.properties
+local.properties
+project.properties
+
+# Eclipse project files
+.classpath
+.project
+
+# idea project files
+.idea/
+.idea/.name
+*.iml
+*.ipr
+*.iws
+
+#gitignore file
+.gitignore