move ACTION_CARRIER_SETUP intent to public api

As per CDD: The "android.*" namespace for intent constants is reserved for public
Android API in AOSP. (Whether public to the full SDK, @SystemApi or
defined in AOSP support libraries.)
ACTION_CARRIER_SETUP intent is generally useful for carrier privileged
apps which is unbundled carrier apps, thus move to public APIs

Bug: 33679956
Test: Manual
Change-Id: Ie2b5d072406513f04676210d08c43d91623c3cd2