Since PerformanceManager is strictly a CyanogenMod construct,
it doesn't make sense to enforce the interfaces with an android
specific permission (even though the implementation is delegated
to power manager). To keep consistency with the other api's,
modify the enforcing permission to a cm specific declaration.
Also add test cases for the PerformanceManager public interfaces.
Change-Id: I430b69dbee73bf94bb60932d1942ab97e3ba193e
b4eafda7de