Samples Build: Exclude bin and .iml files for emitGradle

- Prevent "bin" from showing up in .zip files.
- Prevent IntelliJ projects from propagating into .zip files.

Change-Id: Idd508120c3ed00145f4f8ff4dd3f99fb4349d3fb
diff --git a/build.gradle b/build.gradle
index 9523a99..d643cd0 100644
--- a/build.gradle
+++ b/build.gradle
@@ -129,9 +129,11 @@
         // Paths to exclude from output
         exclude ".gradle"
         exclude "_index.jd"
+        exclude "bin"
         exclude "buildSrc"
         exclude "local.properties"
         exclude "template-params.xml"
+        exclude "*.iml"
         exclude "**/build"
         exclude "**/proguard-project.txt"
         exclude "${samplegen.targetSampleModule()}/**/README*.txt"