Allow end-users to override yielded number logic

[hhff]

In order to override how the lib finds the device's phone number, this PR allows end users to do this:

com.klinker.android.send_message.Utils.setOwnNumberOverride(new com.klinker.android.send_message.OwnNumber() {
   @Override
   public String onYield(Context context) {
       return myCustomResolveNumberLogic();
   }
});

[hhff]

This was the only part I was a little sketchy on. In this implementation, the lib will still call getLine1NumberForSubscriber rather than Utils.getMyPhoneNumber

How do you think we should handle this?

[klinker24]

This is used for dual SIM devices, and we don't want to lose this functionality. I would probably make some kind of condition here

1. If the user has more than one SIM card, then use this original reflection. You can find how many sim cards the user has, by querying this method and getting the length of the array: https://developer.android.com/reference/android/telephony/SubscriptionManager.html#getActiveSubscriptionInfoList()
2. If the user has not provided a custom override, then use this original reflection.

So, only use the new Utils.getMyPhoneNumber(context) if the user has one SIM card and the implementing app has actually provided an override.

[hhff]

thanks Luke! will look to find some time this weekend to finish it off 🙂

[kangnaclub9]

coply