release: Update package.xml version to 1.2.7

package.xml

 <?xml version="1.0"?>
 <package format="3">
   <name>sot-application</name>
-  <version>1.2.6</version>
+  <version>1.2.7</version>
   <description>
      Application dependent control graph initialization scripts for the SoT
   </description>