match js sdk behavior in getAccessToken:

"Returns the current token if it has not expired or if it will not expire in the next five minutes. Otherwise, this will refresh the token and return a new one."

Author: nbransby

gradle.properties

@@ -1 +1 @@
-version=0.1.1
+version=0.1.2

src/main/java/com/google/firebase/auth/FirebaseAuth.kt

@@ -243,7 +243,7 @@ class FirebaseAuth constructor(val app: FirebaseApp) : InternalAuthProvider {
         val source = TaskCompletionSource<GetTokenResult>()
         val user = user ?: return Tasks.forException(FirebaseNoSignedInUserException("Please sign in before trying to get a token."))
 
-        if (!forceRefresh || user.createdAt + user.expiresIn * 1000 * 0.90 > System.currentTimeMillis()) {
+        if (!forceRefresh && user.createdAt + user.expiresIn - 5*60 > System.currentTimeMillis() / 1000) {
 //            Log.i("FirebaseAuth", "returning existing token for user ${user.uid} from getAccessToken")
             return Tasks.forResult(GetTokenResult(user.idToken, user.claims))
         }