gitignore, add more Android build and release locations.

.gitignore

@@ -57,6 +57,10 @@ unlinked_spec.ds
 **/android/**/GeneratedPluginRegistrant.java
 **/android/key.properties
 *.jks
+android/build
+android/app/build
+android/release
+android/app/release
 
 # iOS/XCode related
 **/ios/**/*.mode1v3