Apply delivery group policies to ACTION_DISCOVERY_FINISHED.

- The "set-defer-until-active" policy is applied so that the
broadcast targeted to apps in the Cached state is deferred until
they come out of that state.
- The "deliver-most-recent" policy is applied so that if there are
already pending broadcasts waiting to be delivered when a new
broadcast is sent, the old ones are discarded.

Bug: 266474854
Test: atest CtsBluetoothTestCases
Change-Id: Iaa505809fdb2f67a440a9a568fd44a753814b0e2