Support Queue Strategy on Android and iOS

[EnzoMenegaldo]

Pull request checklist

Please check if your PR fulfills the following requirements:

• The changes have been tested successfully.

Until now, when the speak method was called, it interrupted any requests in progress that had not been completed.
The aim is to allow the user to choose between two strategies:

• 0: Stop the current request when a new request is called.
• 1: Queue the request if another request is in progress. It will start when all previous requests have been completed.

[robingenz]

@EnzoMenegaldo Have you tested your changes? I ask because you did not check the box.

[EnzoMenegaldo]

@EnzoMenegaldo Have you tested your changes? I ask because you did not check the box.

Yes @robingenz I have tested on iOS and Android.