React-Native and Intl polyfill required on Android device

Instead of importing locale-data from react-intl, I have resolved the issue importing the polyfill and the locale data from intl

Install intl

npm install intl

Add this at the very top of your app:

import 'intl';
import 'intl/locale-data/jsonp/en';

Heads up, this works now with just doing the import 'intl'; at the top and still loading the locale-data from react-intl. Using the following versions:

"intl": "^1.2.5",
"react-intl": "^2.2.2",

Modifying the "build.gradle"

On android, you can modify the "build.gradle" file inside /android/app/build.gradle. Remember, it is NOT the file in /android/app/gradle/build.gradle.

then, go to the sited file and search for:

      /**
     * The preferred build flavor of JavaScriptCore.
     *
     * For example, to use the international variant, you can use:
     * `def jscFlavor = 'org.webkit:android-jsc-intl:+'`
     *
     * The international variant includes ICU i18n library and necessary data
     * allowing to use e.g. `Date.toLocaleString` and `String.localeCompare` that
     * give correct results when using with locales other than en-US.  Note that
     * this variant is about 6MiB larger per architecture than default.
     */
     def jscFlavor = 'org.webkit:android-jsc:+'

now, modify the last line, or simply comment it out and copy and paste the similar one above. And the result will be this:

      /**
     * The preferred build flavor of JavaScriptCore.
     *
     * For example, to use the international variant, you can use:
     * `def jscFlavor = 'org.webkit:android-jsc-intl:+'`
     *
     * The international variant includes ICU i18n library and necessary data
     * allowing to use e.g. `Date.toLocaleString` and `String.localeCompare` that
     * give correct results when using with locales other than en-US.  Note that
     * this variant is about 6MiB larger per architecture than default.
     */
     //def jscFlavor = 'org.webkit:android-jsc:+'
     def jscFlavor = 'org.webkit:android-jsc-intl:+'