Add paddingTop to android ToolBar. (#2266)

* Add paddingTop to android ToolBar.

* Update documentation

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

     public int titleBarHeight;
     public boolean backButtonHidden;
     public Font titleBarButtonFontFamily;
+    public int titleBarTopPadding;
 
     public Color topTabTextColor;
     public Font topTabTextFontFamily;

android/app/src/main/java/com/reactnativenavigation/params/parsers/StyleParamsParser.java

         result.titleBarHeight = getInt("titleBarHeight", getDefaultTitleBarHeight());
         result.backButtonHidden = getBoolean("backButtonHidden", getDefaultBackButtonHidden());
         result.topTabsHidden = getBoolean("topTabsHidden", getDefaultTopTabsHidden());
+        result.titleBarTopPadding = getInt("titleBarTopPadding", getTitleBarTopPadding());
 
         result.topTabTextColor = getColor("topTabTextColor", getDefaultTopTabTextColor());
         result.topTabTextFontFamily = getFont("topTabTextFontFamily", getDefaultTopTabTextFontFamily());
         return AppStyle.appStyle == null ? -1 : AppStyle.appStyle.titleBarHeight;
     }
 
+    private int getTitleBarTopPadding() {
+        return AppStyle.appStyle == null ? 0 : AppStyle.appStyle.titleBarTopPadding;
+    }
+
     private boolean getBoolean(String key, boolean defaultValue) {
         return params.containsKey(key) ? params.getBoolean(key) : defaultValue;
     }

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

         colorOverflowButton(params);
         setBackground(params);
         centerTitle(params);
+        setTopPadding(params);
     }
 
     public void setVisibility(boolean titleBarHidden) {
         });
     }
 
+    private void setTopPadding(final StyleParams params) {
+        setPadding(0, params.titleBarTopPadding, 0,0);
+    }
+
     private void colorOverflowButton(StyleParams params) {
         Drawable overflowIcon = actionMenuView.getOverflowIcon();
         if (shouldColorOverflowButton(params, overflowIcon)) {

docs/styling-the-navigator.md

   collapsingToolBarCollapsedColor: '#0f2362', // Collapsing Toolbar scrim color.
   navBarTextFontBold: false, // Optional. Set the title to bold.
   navBarHeight: 70, // Optional, set the navBar height in pixels.
+  navBarTopPadding: 24, // Optional, set navBar top padding in pixels. Useful when StatusBar.translucent=true on Android Lollipop and above.
   topTabsHeight: 70, // Optional, set topTabs height in pixels.
   topBarBorderColor: 'red', Optional, set a flat border under the TopBar.
   topBarBorderWidth: 5.5, // Optional, set the width of the border.

src/deprecated/platformSpecificDeprecated.android.js

     titleBarTitleFontBold: originalStyleObject.navBarTextFontBold,
     titleBarTitleTextCentered: originalStyleObject.navBarTitleTextCentered,
     titleBarHeight: originalStyleObject.navBarHeight,
+    titleBarTopPadding: originalStyleObject.navBarTopPadding,
     backButtonHidden: originalStyleObject.backButtonHidden,
     topTabsHidden: originalStyleObject.topTabsHidden,
     contextualMenuStatusBarColor: processColor(originalStyleObject.contextualMenuStatusBarColor),