Adding gitignore
Adding gitignore

Change-Id: I548a00b89e915d2937808e4f690f8e3e47d867fa

hbmartin/sub9-client,AJHill37/LFG,firebase/quickstart-android,firebase/quickstart-android,AJHill37/LFG,samtstern/quickstart-android,firebase/quickstart-android,samtstern/quickstart-android,firebase/quickstart-android,firebase/quickstart-android,samtstern/quickstart-android,firebase/quickstart-android,hbmartin/sub9-client,AJHill37/LFG