[Bug] A mute button in Rewarded ad does not mute/unmute ad audio

[euisong-jung-navercorp]

Describe the bug
Whenever a user clicks on mute button in rewarded ad, the button image is toggled but the ad audio keeps playing.

To Reproduce
Steps to reproduce the behavior:

1. Integrate Prebid Mobile Android 3.3.1 and load a rewarded ad.

2. Configure the returned AdUnitConfiguration before rendering:

   val configuration = response.adUnitConfiguration.apply {
       setIsSoundButtonVisible(true)
       setIsMuted(false)
   }

3. Render the bid response with InterstitialController.loadAd(configuration, response).

4. Show the rewarded ad.

5. Tap mute button to toggle ad audio.

6. Observe that audio is playing, while the sound button icon is toggled.

Smartphone (please complete the following information):

• Device: Samsung Galaxy S23
• OS: Android 16
• Browser: N/A (native Android app)
• Version: Prebid Mobile Android 3.3.1

Additional context
There was an similar issue but other ad format(Video banner) in #438.