[TIMOB-27519] Android: Semantic Colors with alpha value

   {
       "mainColor": {
           "dark": {
               "color: "#000000",
               "alpha: "50"
           },
           "light": {
               "color: "#ffffff",
               "alpha: "50"
           }
       }
   }
   

   (function() {
     const osVersion = parseInt(Ti.Platform.version.split('.')[0]);
   
     if (Ti.App.iOS && osVersion >= 13) {
       return;
     }
     const colorset = require('/semantic.colors.json');
     const shorthandRegex = /^#?([a-f\d])([a-f\d])([a-f\d])$/i;
     const fallbackColor = 'black'; // To match iphone/Classes/TiUIiOSProxy.m#fetchSemanticColor
   
     const hexToRgb = function hexToRgb(hex) {
       let alpha = 1;
       let color = hex;
       if (hex.color) {
         alpha = hex.alpha / 100; // convert from 0-100 range to 0-1 range
         color = hex.color;
       }
       // Expand shorthand form (e.g. "03F") to full form (e.g. "0033FF")
       color = color.replace(shorthandRegex, (m, r, g, b) => r + r + g + g + b + b);
   
       const r = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(color);
       return r ? rgba(${parseInt(r[1], 16)}, ${parseInt(r[2], 16)}, ${parseInt(r[3], 16)}, ${alpha.toFixed(3)}): null;
     };
     Ti.UI.fetchSemanticColor = function(name) {
       if (!colorset[name]) {
         return fallbackColor;
       }
       const color = colorset[name][Ti.UI.semanticColorType];
       if (typeof color === 'string') {
         return color;
       }
       if (!color || typeof color !== 'object') {
         return fallbackColor;
       }
       if (color['color'] && color['alpha']) {
         const result = hexToRgb(color);
         if (result) {
           return result;
         }
       }
       return fallbackColor;
     }
   })();
   
   if (Alloy && Alloy.CFG && Alloy.CFG.color) {
     const colorset = require('/semantic.colors.json');
   
     Object.keys(colorset).forEach(name => {
       const color = Ti.UI.fetchSemanticColor(name);
       console.log(Alloy.CFG.color[${name}]: ${color});
       Alloy.CFG.color[name] = color;
     });
   }