Add availability annotations

Author: colemancda

Sources/AndroidBluetooth/BluetoothAdapter.swift

@@ -73,23 +73,23 @@ open class BluetoothAdapter: JavaObject {
   ///
   /// - Since: API Level 18
   /// - Deprecated: Use `BluetoothLeScanner.startScan()` instead (API 21+)
-  @available(Android 18, deprecated: 21, message: "Use BluetoothLeScanner.startScan() instead")
+  @available(Android, introduced: 18, deprecated: 21, message: "Use BluetoothLeScanner.startScan() instead")
   @JavaMethod
   open func startLeScan(_ arg0: [UUID?], _ arg1: BluetoothAdapter.LeScanCallback?) -> Bool
 
   /// Starts a scan for Bluetooth LE devices.
   ///
   /// - Since: API Level 18
   /// - Deprecated: Use `BluetoothLeScanner.startScan()` instead (API 21+)
-  @available(Android 18, deprecated: 21, message: "Use BluetoothLeScanner.startScan() instead")
+  @available(Android, introduced: 18, deprecated: 21, message: "Use BluetoothLeScanner.startScan() instead")
   @JavaMethod
   open func startLeScan(_ arg0: BluetoothAdapter.LeScanCallback?) -> Bool
 
   /// Stops an ongoing Bluetooth LE device scan.
   ///
   /// - Since: API Level 18
   /// - Deprecated: Use `BluetoothLeScanner.stopScan()` instead (API 21+)
-  @available(Android 18, deprecated: 21, message: "Use BluetoothLeScanner.stopScan() instead")
+  @available(Android, introduced: 18, deprecated: 21, message: "Use BluetoothLeScanner.stopScan() instead")
   @JavaMethod
   open func stopLeScan(_ arg0: BluetoothAdapter.LeScanCallback?)
 

Sources/AndroidBluetooth/BluetoothLeAudio.swift

@@ -33,6 +33,7 @@ open class BluetoothLeAudio: JavaObject {
   @JavaMethod
   open func close()
 }
+@available(Android 33, *)
 extension JavaClass<BluetoothLeAudio> {
   @JavaStaticField(isFinal: true)
   public var ACTION_LE_AUDIO_CONNECTION_STATE_CHANGED: String