Don't set userSetLocale from Configuration.setLocale.

This seems to have been a mistake : userSetLocale controls whether
a locale is persisted and as written it's too easy to make system wide
locale changes without intending to. Third party apps do not have
sufficient permissions to set global locales anyway, so they won't care
whether it's set or not.

Also, set userSetLocale = true in the LocalePicker.updateLocale internal
API, which is what all platform apps use to set the locale.

In addition, this commit fixes a bug where we were not setting RTL
directionality for the default locale loaded by the activity manager
service.

Change-Id: I2e11ad31e012dfa314ab8d78034f986b49ecae60