.get() method returns a list instead of a dict in Realtime Database

### [REQUIRED] Step 2: Describe your environment

* Operating System version: windows 11
* Firebase SDK version: 6.1.0
* Firebase Product: Realtime Database
* Python version: 3.9
* Pip version: pip 23.0.1

### [REQUIRED] Step 3: Describe the problem

#### Steps to reproduce:

If you set a key in Realtime Database with a value like this: {"1": "value1", "2": "value2"} and use .get() to retrieve the value, you will receive a list [None, "value1", "value2"] instead of a dict. In addition, it seems that if you use keys that are either too far apart as integers or if you put 0 before a number, you won't get a list.
#### Relevant Code:

```
data.ref.child("key").set({"1": "Hello", "2": "World!"})
print(data.ref.child("key").get())
```

Start by reproducing the reported behavior with the Realtime Database .get() call and the provided Python snippet, then inspect the implementation behind data.ref.child("key").get(). Done means retrieving {"1": "Hello", "2": "World!"} returns a dict rather than [None, "Hello", "World!"], while also checking the described integer-key variations.

Written by the indexing model from the issue text.