Move HCI setup to new adafruit_airlift library

Author: dhalbert

adafruit_ble/__init__.py

@@ -156,13 +156,12 @@ class BLERadio:
     It uses this library's `Advertisement` classes and the `BLEConnection` class."""
 
     def __init__(self, adapter=None):
-        if not _bleio.adapter:
-            # Try setting up an onboard HCI BLE adapter.
-            from adafruit_ble import hci  # pylint: disable=import-outside-toplevel
-
-            adapter = hci.create_adapter()
-            _bleio.set_adapter(adapter)  # pylint: disable=no-member
-        self._adapter = adapter
+        """If no adapter is supplied, use the built-in _bleio.adapter, if available.
+        If not, see if there's an onboard HCI adapter available that could be used.
+        """
+        if adapter is None and _bleio.adapter is None:
+            raise RuntimeError("No adapter available")
+        self._adapter = adapter or _bleio.adapter
         self._current_advertisement = None
         self._connection_cache = {}
 
@@ -190,6 +189,7 @@ def start_advertising(
         if scan_response:
             scan_response_bytes = bytes(scan_response)
 
+        # pylint: disable=unexpected-keyword-arg
         # Remove after 5.x is no longer supported.
         if (
             sys.implementation.name == "circuitpython"
@@ -351,4 +351,4 @@ def address_bytes(self):
     @property
     def advertising(self):
         """The advertising state"""
-        return self._adapter.advertising
+        return self._adapter.advertising  # pylint: disable=no-member