update dexcount-gradle-plugin to 0.7.3

Author: Manabu-GT

build.gradle

@@ -9,7 +9,7 @@ buildscript {
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
-        classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:0.6.3'
+        classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:0.7.3'
     }
 }