Add @Nullable to BluetoothAdapter provider.

Test: compilation and StylusManagerTest
Bug: 263451493
Change-Id: I57c467566afa5635aced88eb6ed322a55cd59938
diff --git a/packages/SystemUI/src/com/android/systemui/dagger/FrameworkServicesModule.java b/packages/SystemUI/src/com/android/systemui/dagger/FrameworkServicesModule.java
index 2260e35..4bb5d04 100644
--- a/packages/SystemUI/src/com/android/systemui/dagger/FrameworkServicesModule.java
+++ b/packages/SystemUI/src/com/android/systemui/dagger/FrameworkServicesModule.java
@@ -636,6 +636,7 @@
 
     @Provides
     @Singleton
+    @Nullable
     static BluetoothAdapter provideBluetoothAdapter(BluetoothManager bluetoothManager) {
         return bluetoothManager.getAdapter();
     }
diff --git a/packages/SystemUI/src/com/android/systemui/stylus/StylusManager.kt b/packages/SystemUI/src/com/android/systemui/stylus/StylusManager.kt
index 3e111e6..302d6a9 100644
--- a/packages/SystemUI/src/com/android/systemui/stylus/StylusManager.kt
+++ b/packages/SystemUI/src/com/android/systemui/stylus/StylusManager.kt
@@ -38,7 +38,7 @@
 @Inject
 constructor(
     private val inputManager: InputManager,
-    private val bluetoothAdapter: BluetoothAdapter,
+    private val bluetoothAdapter: BluetoothAdapter?,
     @Background private val handler: Handler,
     @Background private val executor: Executor,
 ) : InputManager.InputDeviceListener, BluetoothAdapter.OnMetadataChangedListener {
@@ -141,7 +141,7 @@
     }
 
     private fun onStylusBluetoothConnected(btAddress: String) {
-        val device: BluetoothDevice = bluetoothAdapter.getRemoteDevice(btAddress) ?: return
+        val device: BluetoothDevice = bluetoothAdapter?.getRemoteDevice(btAddress) ?: return
         try {
             bluetoothAdapter.addOnMetadataChangedListener(device, executor, this)
         } catch (e: IllegalArgumentException) {
@@ -150,7 +150,7 @@
     }
 
     private fun onStylusBluetoothDisconnected(btAddress: String) {
-        val device: BluetoothDevice = bluetoothAdapter.getRemoteDevice(btAddress) ?: return
+        val device: BluetoothDevice = bluetoothAdapter?.getRemoteDevice(btAddress) ?: return
         try {
             bluetoothAdapter.removeOnMetadataChangedListener(device, this)
         } catch (e: IllegalArgumentException) {