Implement a synchronous UiImplementation

Related to #2892

To use it, Override `createReactNativeHost` in MainApplication as follows:

```java
    @Override
    protected ReactNativeHost createReactNativeHost() {
        return new NavigationReactNativeHost(this) {
            @Override
            protected UIImplementationProvider getUIImplementationProvider() {
                return new SyncUiImplementation.Provider();
            }
        };
    }
```

lib/android/app/src/main/java/com/reactnativenavigation/react/SyncUiImplementation.java

@@ -0,0 +1,83 @@
+package com.reactnativenavigation.react;
+
+import android.support.annotation.Nullable;
+
+import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.bridge.ReadableArray;
+import com.facebook.react.bridge.ReadableMap;
+import com.facebook.react.uimanager.MeasureSpecProvider;
+import com.facebook.react.uimanager.SizeMonitoringFrameLayout;
+import com.facebook.react.uimanager.ThemedReactContext;
+import com.facebook.react.uimanager.UIImplementation;
+import com.facebook.react.uimanager.UIImplementationProvider;
+import com.facebook.react.uimanager.UIManagerModule;
+import com.facebook.react.uimanager.ViewManager;
+import com.facebook.react.uimanager.events.EventDispatcher;
+
+import java.util.List;
+
+@SuppressWarnings("WeakerAccess")
+public class SyncUiImplementation extends UIImplementation {
+    private static final Object lock = new Object();
+
+    public static class Provider extends UIImplementationProvider {
+        @Override
+        public UIImplementation createUIImplementation(ReactApplicationContext reactContext, List<ViewManager> viewManagerList, EventDispatcher eventDispatcher, int minTimeLeftInFrameForNonBatchedOperationMs) {
+            return new SyncUiImplementation(reactContext, viewManagerList, eventDispatcher, minTimeLeftInFrameForNonBatchedOperationMs);
+        }
+
+        @Override
+        public UIImplementation createUIImplementation(ReactApplicationContext reactContext, UIManagerModule.ViewManagerResolver viewManagerResolver, EventDispatcher eventDispatcher, int minTimeLeftInFrameForNonBatchedOperationMs) {
+            return new SyncUiImplementation(reactContext, viewManagerResolver, eventDispatcher, minTimeLeftInFrameForNonBatchedOperationMs);
+        }
+    }
+
+    public SyncUiImplementation(ReactApplicationContext reactContext, List<ViewManager> viewManagerList, EventDispatcher eventDispatcher, int minTimeLeftInFrameForNonBatchedOperationMs) {
+        super(reactContext, viewManagerList, eventDispatcher, minTimeLeftInFrameForNonBatchedOperationMs);
+    }
+
+    public SyncUiImplementation(ReactApplicationContext reactContext, UIManagerModule.ViewManagerResolver viewManagerResolver, EventDispatcher eventDispatcher, int minTimeLeftInFrameForNonBatchedOperationMs) {
+        super(reactContext, viewManagerResolver, eventDispatcher, minTimeLeftInFrameForNonBatchedOperationMs);
+    }
+
+    @Override
+    public void manageChildren(
+            int viewTag,
+            @Nullable ReadableArray moveFrom,
+            @Nullable ReadableArray moveTo,
+            @Nullable ReadableArray addChildTags,
+            @Nullable ReadableArray addAtIndices,
+            @Nullable ReadableArray removeFrom) {
+        synchronized (lock) {
+            super.manageChildren(viewTag, moveFrom, moveTo, addChildTags, addAtIndices, removeFrom);
+        }
+    }
+
+    @Override
+    public void setChildren(int viewTag, ReadableArray childrenTags) {
+        synchronized (lock) {
+            super.setChildren(viewTag, childrenTags);
+        }
+    }
+
+    @Override
+    public void createView(int tag, String className, int rootViewTag, ReadableMap props) {
+        synchronized (lock) {
+            super.createView(tag, className, rootViewTag, props);
+        }
+    }
+
+    @Override
+    public void removeRootShadowNode(int rootViewTag) {
+        synchronized (lock) {
+            super.removeRootShadowNode(rootViewTag);
+        }
+    }
+
+    @Override
+    public <T extends SizeMonitoringFrameLayout & MeasureSpecProvider> void registerRootView(T rootView, int tag, ThemedReactContext context) {
+        synchronized (lock) {
+            super.registerRootView(rootView, tag, context);
+        }
+    }
+}

playground/android/app/src/main/java/com/reactnativenavigation/playground/MainApplication.java

@@ -4,8 +4,10 @@ import android.support.annotation.Nullable;
 
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
+import com.facebook.react.uimanager.UIImplementationProvider;
 import com.reactnativenavigation.NavigationApplication;
 import com.reactnativenavigation.react.NavigationReactNativeHost;
+import com.reactnativenavigation.react.SyncUiImplementation;
 
 import java.util.List;
 
@@ -24,6 +26,11 @@ public class MainApplication extends NavigationApplication {
             protected String getJSMainModuleName() {
                 return "index";
             }
+
+            @Override
+            protected UIImplementationProvider getUIImplementationProvider() {
+                return new SyncUiImplementation.Provider();
+            }
         };
     }