android: support chooseAudioRoute() and onAudioDeviceChanged event

** chooseAudioRoute() let user choose their own audio route

param: "EARPIECE", "SPEAKER_PHONE", "WIRED_HEADSET", "BLUETOOTH"
if a audio device is unavailable, it will do nothing.

if success, it will return a promise contains an object like
`onAudioDeviceChanged`'s data below.

** onAudioDeviceChanged Event

Will fire event to JS, indicating current available audio devices.
and current selected audio devices. your UI can display available options
according to these data.

Note for writableArray issue,
`availableAudioDeviceList` is a JSON Array String
so you need to `JSON.parse()` it before you use it as an array object in js

example:

```
{
	"availableAudioDeviceList": "[\"EARPIECE\", \"SPEAKER_PHONE\"]",
	"selectedAudioDevice": "SPEAKER_PHONE",
}
```

Author: zxcpoiu

android/src/main/java/com/zxcpoiu/incallmanager/InCallManagerModule.java

@@ -1468,6 +1468,22 @@ public void requestCameraPermission(Promise promise) {
         }
     }
 
+    @ReactMethod
+    public void chooseAudioRoute(String audioRoute, Promise promise) {
+        Log.d(TAG, "RNInCallManager.chooseAudioRoute(): user choose audioDevice = " + audioRoute);
+
+        if (audioRoute.equals(AudioDevice.EARPIECE.name())) {
+            selectAudioDevice(AudioDevice.EARPIECE);
+        } else if (audioRoute.equals(AudioDevice.SPEAKER_PHONE.name())) {
+            selectAudioDevice(AudioDevice.SPEAKER_PHONE);
+        } else if (audioRoute.equals(AudioDevice.WIRED_HEADSET.name())) {
+            selectAudioDevice(AudioDevice.WIRED_HEADSET);
+        } else if (audioRoute.equals(AudioDevice.BLUETOOTH.name())) {
+            selectAudioDevice(AudioDevice.BLUETOOTH);
+        }
+        promise.resolve(getAudioDeviceStatusMap());
+    }
+
     private void _requestPermission(String targetPermission, Promise promise) {
         Activity currentActivity = getCurrentActivity();
         if (currentActivity == null) {
@@ -1644,7 +1660,8 @@ public void setDefaultAudioDevice(AudioDevice defaultDevice) {
     /** Changes selection of the currently active audio device. */
     public void selectAudioDevice(AudioDevice device) {
         if (!audioDevices.contains(device)) {
-            Log.e(TAG, "Can not select " + device + " from available " + audioDevices);
+            Log.e(TAG, "selectAudioDevice() Can not select " + device + " from available " + audioDevices);
+            return;
         }
         userSelectedAudioDevice = device;
         updateAudioDeviceState();
@@ -1870,7 +1887,26 @@ public void updateAudioDeviceState() {
                 audioManagerEvents.onAudioDeviceChanged(selectedAudioDevice, audioDevices);
             }
             */
+            sendEvent("onAudioDeviceChanged", getAudioDeviceStatusMap());
         }
         Log.d(TAG, "--- updateAudioDeviceState done");
     }
+
+    private WritableMap getAudioDeviceStatusMap() {
+        WritableMap data = Arguments.createMap();
+        String audioDevicesJson = "[";
+        for (AudioDevice s: audioDevices) {
+            audioDevicesJson += "\"" + s.name() + "\",";
+        }
+        // --- strip the last `,`
+        if (audioDevicesJson.length() > 1) {
+            audioDevicesJson = audioDevicesJson.substring(0, audioDevicesJson.length() - 1);
+        }
+        audioDevicesJson += "]";
+
+        data.putString("availableAudioDeviceList", audioDevicesJson);
+        data.putString("selectedAudioDevice", selectedAudioDevice.name());
+
+        return data;
+    }
 }

index.js

@@ -171,6 +171,11 @@ class InCallManager {
             }
         }
     }
+
+    async chooseAudioRoute(route) {
+        let result = await _InCallManager.chooseAudioRoute(route);
+        return result;
+    }
 }
 
 export default new InCallManager();