feat(Android): Add flush method on Android (#64)

BREAKING CHANGE: Android Minmum SDK bumped to API 21

README.md

@@ -164,6 +164,12 @@ CookieManager.clearByName('http://example.com', 'cookie_name')
   .then((success) => {
     console.log('CookieManager.clearByName =>', success);
   });
+
+// flush cookies (ANDROID ONLY)
+CookieManager.flush()
+  .then((success) => {
+    console.log('CookieManager.flush =>', success);
+  });
 ```
 
 ### WebKit-Support (iOS only)

android/build.gradle

@@ -14,7 +14,7 @@ import groovy.json.JsonSlurper
 
 def DEFAULT_COMPILE_SDK_VERSION = 29
 def DEFAULT_BUILD_TOOLS_VERSION = '29.0.3'
-def DEFAULT_MIN_SDK_VERSION = 16
+def DEFAULT_MIN_SDK_VERSION = 21
 def DEFAULT_TARGET_SDK_VERSION = 29
 
 def safeExtGet(prop, fallback) {

android/src/main/java/com/reactnativecommunity/cookies/CookieManagerModule.java

@@ -85,6 +85,16 @@ public void setFromResponse(String url, String cookie, final Promise promise) {
         addCookies(url, cookie, promise);
     }
 
+    @ReactMethod
+    public void flush(Promise promise) {
+        try {
+            mCookieManager.flush();
+            promise.resolve(true);
+        } catch (Exception e) {
+            promise.reject(e);
+        }
+    }
+
     @ReactMethod
     public void getFromResponse(String url, Promise promise) throws URISyntaxException, IOException {
         promise.resolve(url);

index.js

@@ -41,6 +41,11 @@ module.exports = {
     CookieManager.set(url, cookie, useWebKit),
   clearByName: (url, name, useWebKit = false) =>
     CookieManager.clearByName(url, name, useWebKit),
+  flush: async () => {
+    if (Platform.OS === 'android') {
+      await CookieManager.flush();
+    }
+  },
 };
 
 for (var i = 0; i < functions.length; i++) {