InputReader: Get Bluetooth address from InputDeviceIdentifier

The InputDevice class in Reader stores the InputDeviceIdentifier. When
the policy wants to get the Bluetooth address of an InputDevice, fetch
it from there.

Bug: 243005009
Test: atest inputflinger_tests
Change-Id: I5d881a11cb1bc318258faf1f498db1ca29ae8537
diff --git a/services/inputflinger/include/InputReaderBase.h b/services/inputflinger/include/InputReaderBase.h
index 8c586b5..3b0f2ac 100644
--- a/services/inputflinger/include/InputReaderBase.h
+++ b/services/inputflinger/include/InputReaderBase.h
@@ -142,6 +142,9 @@
     virtual std::optional<int32_t> getLightColor(int32_t deviceId, int32_t lightId) = 0;
     /* Get light player ID */
     virtual std::optional<int32_t> getLightPlayerId(int32_t deviceId, int32_t lightId) = 0;
+
+    /* Get the Bluetooth address of an input device, if known. */
+    virtual std::optional<std::string> getBluetoothAddress(int32_t deviceId) const = 0;
 };
 
 // --- InputReaderConfiguration ---