feat(aws-datastore): Make the reachability component configurable

aws-datastore/src/main/java/com/amplifyframework/datastore/AWSDataStorePlugin.java

@@ -755,8 +755,7 @@ Builder storageAdapter(LocalStorageAdapter storageAdapter) {
          * @param reachabilityMonitor An instance that implements LocalStorageAdapter.
          * @return Current builder instance, for fluent construction of plugin.
          */
-        @VisibleForTesting
-        Builder reachabilityMonitor(ReachabilityMonitor reachabilityMonitor) {
+        public Builder reachabilityMonitor(ReachabilityMonitor reachabilityMonitor) {
             this.reachabilityMonitor = reachabilityMonitor;
             return this;
         }

aws-datastore/src/main/java/com/amplifyframework/datastore/syncengine/ReachabilityMonitor.kt

@@ -36,7 +36,7 @@ import java.util.concurrent.TimeUnit
  * The network changes are debounced with a 250 ms delay to allow some time for one network to connect after another
  * network has disconnected (for example, wifi is lost, then cellular connects) to reduce thrashing.
  */
-internal interface ReachabilityMonitor {
+public interface ReachabilityMonitor {
     fun configure(context: Context)
     @VisibleForTesting
     fun configure(context: Context, connectivityProvider: ConnectivityProvider)
@@ -99,7 +99,7 @@ private class ReachabilityMonitorImpl constructor(val schedulerProvider: Schedul
  * is a concrete class created within context.getSystemService() it can't be overridden with a test
  * implementation, so this interface works around that issue.
  */
-internal interface ConnectivityProvider {
+public interface ConnectivityProvider {
     val hasActiveNetwork: Boolean
     fun registerDefaultNetworkCallback(context: Context, callback: NetworkCallback)
 }