Merge changes Ifcb338e6,Ie509ed80,I270fed60,Id825cb75,I92a963bd

* changes:
  Prepare for a type-safe OnceKey
  Add Temporary and DeleteTemporaryFiles to RuleBuilder
  Improve RuleBuilder documentation and methods
  Allow RuleBuilder to be used with SingletonContext
  Move dexpreopt.Script to android.RuleBuilder