Fix bug

Author: schmidt-sebastian

firebase-firestore/src/main/java/com/google/firebase/firestore/model/DatabaseId.java

@@ -43,7 +43,7 @@ private DatabaseId(String projectId, String databaseId) {
   public static DatabaseId fromName(String name) {
     ResourcePath resourceName = ResourcePath.fromString(name);
     hardAssert(
-        resourceName.length() >= 3
+        resourceName.length() > 3
             && resourceName.getSegment(0).equals("projects")
             && resourceName.getSegment(2).equals("databases"),
         "Tried to parse an invalid resource name: %s",