Added ability to specify font size for tab bar labels on Android (#2754)

* Added bottomTabFontSize and bottomTabSelectedFontSize properties for android tab bar

* Added tabFontSize and selectedTabFontSize properties to the doc

* Fix default values of bottomTabFontSize and bottomTabSelectedFontSize properties.

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

     public Color bottomTabBadgeTextColor;
     public Color bottomTabBadgeBackgroundColor;
     public Font bottomTabFontFamily;
+    public Integer bottomTabFontSize;
+    public Integer bottomTabSelectedFontSize;
 
     public Color navigationBarColor;
 

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

         result.forceTitlesDisplay = getBoolean("forceTitlesDisplay", getDefaultForceTitlesDisplay());
 
         result.bottomTabFontFamily = getFont("bottomTabFontFamily", getDefaultBottomTabsFontFamily());
+        result.bottomTabFontSize = getIntegerOrNull("bottomTabFontSize");
+        result.bottomTabSelectedFontSize = getIntegerOrNull("bottomTabSelectedFontSize");
 
         return result;
     }
         result.titleBarHideOnScroll = false;
         result.orientation = Orientation.auto;
         result.bottomTabFontFamily = new StyleParams.Font();
+        result.bottomTabFontSize = 10;
+        result.bottomTabSelectedFontSize = 10;
         result.titleBarTitleFont = new StyleParams.Font();
         result.titleBarSubtitleFontFamily = new StyleParams.Font();
         result.titleBarButtonFontFamily = new StyleParams.Font();
         return params.containsKey(key) ? params.getInt(key) : defaultValue;
     }
 
+    private Integer getIntegerOrNull(String key) {
+        return params.containsKey(key) ? params.getInt(key) : null;
+    }
+
     private Bundle getBundle(String key) {
         return params.containsKey(key) ? params.getBundle(key) : Bundle.EMPTY;
     }

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

         createVisibilityAnimator();
         setStyle();
         setFontFamily();
+        setFontSize();
     }
 
     public void addTabs(List<ScreenParams> params, OnTabSelectedListener onTabSelectedListener) {
             setTitleTypeface(AppStyle.appStyle.bottomTabFontFamily.get());
         }
     }
+
+    private void setFontSize() {
+        if(AppStyle.appStyle.bottomTabSelectedFontSize != null &&  AppStyle.appStyle.bottomTabFontSize != null) {
+            setTitleTextSizeInSp(AppStyle.appStyle.bottomTabSelectedFontSize, AppStyle.appStyle.bottomTabFontSize);
+        }
+    }
 }

android/gradle/wrapper/gradle-wrapper.properties

-#Mon Sep 12 16:05:44 IDT 2016
+#Mon Feb 19 11:46:35 EET 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip

docs/styling-the-tab-bar.md

     tabBarButtonColor: '#ffffff',
     tabBarSelectedButtonColor: '#63d7cc',
     tabBarTranslucent: false,
-    tabFontFamily: 'Avenir-Medium'  // existing font family name or asset file without extension which can be '.ttf' or '.otf' (searched only if '.ttf' asset not found)
+    tabFontFamily: 'Avenir-Medium',  // existing font family name or asset file without extension which can be '.ttf' or '.otf' (searched only if '.ttf' asset not found)
+    tabFontSize: 10,
+    selectedTabFontSize: 12,
   },
 ...
 }

src/deprecated/platformSpecificDeprecated.android.js

     bottomTabBadgeTextColor: processColor(originalStyleObject.bottomTabBadgeTextColor),
     bottomTabBadgeBackgroundColor: processColor(originalStyleObject.bottomTabBadgeBackgroundColor),
     bottomTabFontFamily: originalStyleObject.tabFontFamily,
+    bottomTabFontSize: originalStyleObject.tabFontSize,
+    bottomTabSelectedFontSize: originalStyleObject.selectedTabFontSize,
 
     navigationBarColor: processColor(originalStyleObject.navigationBarColor)
   };