Fix for default text size being set in PX instead of DP

The default text size in ComponentBase was defined as 10 pixels
instead of 10dp, which causes tiny text and does not reflect
the javadoc and the general behavior of setTextSize(...)

MPChartLib/src/main/java/com/github/mikephil/charting/components/ComponentBase.java

@@ -36,7 +36,7 @@ public abstract class ComponentBase {
     /**
      * the text size of the labels
      */
-    protected float mTextSize = 10f;
+    protected float mTextSize = Utils.convertDpToPixel(10f);
 
     /**
      * the text color to use for the labels