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 33679956

Test: Manual
Bug: 33679956
Merged-in: I85dfa99d0b20bb1b534dfe8ead3c274a5c739786
Change-Id: I84ffd5f2c8c3418689ee3d5ff5ddc3f9f7959763