Move the action buttons in installed app detail page in the preference xml.

- instead of dynamically creating the preferences for the action
buttons, add the actions items to the installed app details xml.
- rename the reference as it is no longer a footer.

Change-Id: I41b99f50bcc4916384555b5d9470ac937ff1d2ac
Fix: 36001501
Test: make RunSettingsRoboTests