android: unmute microphone on the ConnectionService handler

This shouldn't be needed, as ConnectionService should take care of it, but we
suspect some devices don't do it since we got reports of people not hearing
users, and the problem went away when CS was disabled.

android/sdk/src/main/java/org/jitsi/meet/sdk/AudioDeviceHandlerConnectionService.java

@@ -17,6 +17,7 @@
 package org.jitsi.meet.sdk;
 
 import android.content.Context;
+import android.media.AudioManager;
 import android.os.Build;
 import android.telecom.CallAudioState;
 import androidx.annotation.RequiresApi;
@@ -38,6 +39,11 @@ class AudioDeviceHandlerConnectionService implements
 
     private final static String TAG = AudioDeviceHandlerConnectionService.class.getSimpleName();
 
+    /**
+     * {@link AudioManager} instance used to interact with the Android audio subsystem.
+     */
+    private AudioManager audioManager;
+
     /**
      * Reference to the main {@code AudioModeModule}.
      */
@@ -134,6 +140,8 @@ class AudioDeviceHandlerConnectionService implements
         JitsiMeetLogger.i("Using " + TAG + " as the audio device handler");
 
         module = audioModeModule;
+        audioManager = (AudioManager)context.getSystemService(Context.AUDIO_SERVICE);
+
         RNConnectionService rcs = ReactInstanceManagerHolder.getNativeModule(RNConnectionService.class);
         if (rcs != null) {
             rcs.setCallAudioStateListener(this);
@@ -160,6 +168,16 @@ class AudioDeviceHandlerConnectionService implements
 
     @Override
     public boolean setMode(int mode) {
+        if (mode != AudioModeModule.DEFAULT) {
+            // This shouldn't be needed when using ConnectionService, but some devices have been
+            // observed not doing it.
+            try {
+                audioManager.setMicrophoneMute(false);
+            } catch (Throwable tr) {
+                JitsiMeetLogger.w(tr, TAG + " Failed to unmute the microphone");
+            }
+        }
+
         return true;
     }
 }