The STK header exit/back button is updated with any proactive command
Declare references at the beginning on the setSTKScreen function
Add a back button to display dialog
Hide alert box is only needed when it's open
Ok button to the right, back button to the left
Merge pull request #7471 from frsela/STK/Bug824136

Bug 824136 - No backward button causes STK GCF test case to fail, r=vingtetun
Merge pull request #7484 from frsela/STK/Bug824136_b

Bug 824136 - No backward button causes STK GCF test case to fail, r=vingtetun
Auto-merge from branch 'master'