all: fix gitignore

Author: abarisain

.gitignore

@@ -28,3 +28,9 @@ build/
 *.ipr
 *.iws
 .idea/
+
+# Sample stuff
+/example/android/app/google-services.json
+/example/android/key.properties
+/example/android/GeneratedPluginRegistrant.java
+/example/android/local.properties

example/android/.gitignore

@@ -2,7 +2,6 @@
 /captures/
 /local.properties
 GeneratedPluginRegistrant.java
-/app/google-services.json
 
 # Remember to never publicly share your keystore.
 # See https://flutter.dev/docs/deployment/android#reference-the-keystore-from-the-app