Add namespace and kotlin options in android/build.gradle for latest g…

[Rumanali786]

…radle version

Thank you for contributing to react-native-purchases. Before pressing the "Create Pull Request" button, please provide the following:

• [ ] This package is not compatible with the latest gradle version.

• [ ] Add the namespace in android/build.gradle

• [ ] Add the jvmtargets in android/build.gradle