Fixed typo
Fixed typo

Changed "Table of Content" to "Table of Contents"
samtstern/FirebaseUI-Android,firebase/FirebaseUI-Android,JosefHruska/FirebaseUI-Android,samtstern/FirebaseUI-Android,SUPERCILEX/FirebaseUI-Android,firebase/FirebaseUI-Android,JosefHruska/FirebaseUI-Android,SUPERCILEX/FirebaseUI-Android,firebase/FirebaseUI-Android,SUPERCILEX/FirebaseUI-Android,SUPERCILEX/FirebaseUI-Android,samtstern/FirebaseUI-Android,firebase/FirebaseUI-Android