Expose ConfigUpdater Intents in SystemApi

The Intents are are in the android namespace and should have been
exposed as SystemApi, but were not previously.

Since there are no classes in the framework that reference these Intents
this adds android.os.ConfigUpdate to have them all in one place.

Test: builds
Change-Id: I2086945301f06b28b491ec876652c37e97315e8c
Fixes: 35252508
Fixes: 35266806
Fixes: 35266833
Fixes: 35271111
(cherry picked from commit 987b0fc4)