change flag name, expose storage for brownfield

Author: Krzysztof Borowy

android/build.gradle

@@ -61,10 +61,10 @@ if( newDbSize != null && newDbSize.isLong()) {
 
 // Instead of reusing AsyncTask thread pool, AsyncStorage can use its own executor
 def useDedicatedExecutor = getFlagOrDefault('AsyncStorage_dedicatedExecutor', false)
-def useNext = getFlagOrDefault("AsyncStorage_useNext", false)
+def useNextStorage = getFlagOrDefault("AsyncStorage_useNextStorage", false)
 
 apply plugin: 'com.android.library'
-if(useNext) {
+if(useNextStorage) {
     apply plugin: 'kotlin-android'
     apply plugin: 'kotlin-kapt'
 }
@@ -77,7 +77,7 @@ android {
         targetSdkVersion safeExtGet('targetSdkVersion', 28)
         buildConfigField "Long", "AsyncStorage_db_size", "${dbSizeInMB}L"
         buildConfigField "boolean", "AsyncStorage_useDedicatedExecutor", "${useDedicatedExecutor}"
-        buildConfigField "boolean", "AsyncStorage_useNext", "${useNext}"
+        buildConfigField "boolean", "AsyncStorage_useNextStorage", "${useNextStorage}"
     }
     lintOptions {
         abortOnError false
@@ -95,7 +95,7 @@ repositories {
 
 dependencies {
 
-    if(useNext) {
+    if(useNextStorage) {
         def room_version = "2.2.6"
         def coroutines_version = "1.3.9"
 

android/src/main/java/com/reactnativecommunity/asyncstorage/AsyncStoragePackage.java

@@ -24,7 +24,7 @@ public List<NativeModule> createNativeModules(ReactApplicationContext reactConte
 
         List<NativeModule> moduleList = new ArrayList<>(1);
 
-        if (BuildConfig.AsyncStorage_useNext) {
+        if (BuildConfig.AsyncStorage_useNextStorage) {
             try {
                 Class storageClass = Class.forName("com.reactnativecommunity.asyncstorage.next.StorageModule");
                 NativeModule inst = (NativeModule) storageClass.getDeclaredConstructor(new Class[]{ReactContext.class}).newInstance(reactContext);

android/src/main/java/com/reactnativecommunity/asyncstorage/next/StorageModule.kt

@@ -1,5 +1,6 @@
 package com.reactnativecommunity.asyncstorage.next
 
+import android.content.Context
 import com.facebook.react.bridge.Arguments
 import com.facebook.react.bridge.Callback
 import com.facebook.react.bridge.ReactContext
@@ -20,10 +21,16 @@ class StorageModule(reactContext: ReactContext) : ReactContextBaseJavaModule(),
 
     private val storage = StorageSupplier.getInstance(reactContext)
 
+    companion object {
+        @JvmStatic
+        fun getStorageInstance(ctx: Context): AsyncStorageAccess {
+            return StorageSupplier.getInstance(ctx)
+        }
+    }
+
     /**
      * Todo:
-     *  - Documenting the migration,
-     *  - access from Native (Java interop)
+     *  - DB tests
      */
 
     @ReactMethod