update gitignore

.gitignore

@@ -1,12 +1,40 @@
-*.iml
-.gradle
-/local.properties
-/.idea/libraries
-/.idea/modules.xml
-/.idea/workspace.xml
-.DS_Store
-/build
+# Project files
 /captures
-.externalNativeBuild
-/app/release
 /tools/config.sh
+
+# Built application files
+*.apk
+*.ap_
+
+# Files for the Dalvik VM
+*.dex
+
+# Java class files
+*.class
+
+# Generated files
+app/release
+bin/
+gen/
+
+# Gradle files
+.gradle/
+build/
+
+# Local configuration file (sdk path, etc)
+local.properties
+
+# Proguard folder generated by Eclipse
+proguard/
+
+# Log Files
+*.log
+
+# IDE and OS files
+.idea/libraries
+.idea/modules.xml
+.idea/workspace.xml
+*.iml
+
+.DS_Store
+.externalNativeBuild