Measure custom react view according to navBarHeight

Fixes #1844

android/app/src/main/java/com/reactnativenavigation/params/StyleParams.java

     public boolean hasTopBarCustomComponent() {
         return !TextUtils.isEmpty(topBarReactView);
     }
+
+    public boolean hasCustomTitleBarHeight() {
+        return titleBarHeight != -1;
+    }
 }

android/app/src/main/java/com/reactnativenavigation/views/TopBar.java

             }
             unmountReactView();
             reactView = new Pair<>(styleParams.topBarReactView, createReactView(styleParams));
+            int height = styleParams.hasCustomTitleBarHeight() ? (int) ViewUtils.convertDpToPixel(styleParams.titleBarHeight) : ViewUtils.getToolBarHeight();
             if ("fill".equals(styleParams.topBarReactViewAlignment)) {
-                addReactViewFill(reactView.second);
+                addReactViewFill(reactView.second, height);
             } else {
-                addCenteredReactView(reactView.second);
+                addCenteredReactView(reactView.second, height);
             }
         } else {
             unmountReactView();
         );
     }
 
-    private void addReactViewFill(ContentView view) {
-        view.setLayoutParams(new LayoutParams(MATCH_PARENT, ViewUtils.getToolBarHeight()));
+    private void addReactViewFill(ContentView view, int height) {
+        view.setLayoutParams(new LayoutParams(MATCH_PARENT, height));
         titleBar.addView(view);
     }
 
-    private void addCenteredReactView(final ContentView view) {
-        titleBar.addView(view, new LayoutParams(WRAP_CONTENT, ViewUtils.getToolBarHeight()));
+    private void addCenteredReactView(final ContentView view, int height) {
+        titleBar.addView(view, new LayoutParams(WRAP_CONTENT, height));
         view.setOnDisplayListener(new Screen.OnDisplayListener() {
             @Override
             public void onDisplay() {