move BuildUtils to WPUtils subtree, rename BuildUtils to PackageUtils…

… and add getPackageInfo and getVersionCode methods

WordPressUtils/src/main/java/org/wordpress/android/util/PackageUtils.java

@@ -0,0 +1,45 @@
+package org.wordpress.android.util;
+
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+
+public class PackageUtils {
+    /**
+     * Return true if Debug build. false otherwise.
+     */
+    public static boolean isDebugBuild() {
+        return BuildConfig.DEBUG;
+    }
+
+    public static PackageInfo getPackageInfo(Context context) {
+        try {
+            PackageManager manager = context.getPackageManager();
+            return manager.getPackageInfo(context.getPackageName(), 0);
+        } catch (PackageManager.NameNotFoundException e) {
+            return null;
+        }
+    }
+
+    /**
+     * Return version code, or 0 if it can't be read
+     */
+    public static int getVersionCode(Context context) {
+        PackageInfo packageInfo = getPackageInfo(context);
+        if (packageInfo != null) {
+            return packageInfo.versionCode;
+        }
+        return 0;
+    }
+
+    /**
+     * Return version name, or the string "0" if it can't be read
+     */
+    public static String getVersionName(Context context) {
+        PackageInfo packageInfo = getPackageInfo(context);
+        if (packageInfo != null) {
+            return packageInfo.versionName;
+        }
+        return "0";
+    }
+}