Add Exception handling

[YukiAttano]

Please catch all library related exceptions and convert them to custom ones.

The following is thrown if InAppUpdate.checkForUpdate() is called in debug build e.g. in a version that is not installed via Google Play

PlatformException(TASK_FAILURE, -10: Install Error(-10): The app is not owned by any user on this device.

[saibotma]

Yeah, it would be great if the exceptions included the error code like ERROR_APP_NOT_OWNED and others from https://developer.android.com/reference/com/google/android/play/core/install/model/InstallErrorCode.