public void getCount(final Promise promise) {
        getExecutor().execute(() -> {
            Context context = getReactApplicationContext();
            ContentResolver cr = context.getContentResolver();
            ContactsProvider contactsProvider = new ContactsProvider(cr);
            try {
                Integer contacts = contactsProvider.getContactsCount();
                promise.resolve(contacts);
            } catch (Exception e) {
                promise.reject(e);
            }
        });
    }
Retrieves contacts.
Uses raw URI when <code>rawUri</code> is <code>true</code>, makes assets copy
otherwise.
android/src/main/java/com/rt2zz/reactnativecontacts/impl/ContactsManagerImpl.java