[Android] Fallback to BLE Notification when Indication unsupported (#…

…25444)

To support devices based on older revisions of the SDK that did not
include the GATT Server Characteristic property change (from
Notification to Indication), the GATT Characteristic properties are
queried to determine if Indication and/or Notification is supported.
When available, Indication is preferred.

src/platform/android/java/chip/platform/AndroidBleManager.java

@@ -157,6 +157,9 @@ public void onDescriptorWrite(
             if (desc.getValue() == BluetoothGattDescriptor.ENABLE_INDICATION_VALUE) {
               mPlatform.handleSubscribeComplete(
                   connId, svcIdBytes, charIdBytes, status == BluetoothGatt.GATT_SUCCESS);
+            } else if (desc.getValue() == BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE) {
+              mPlatform.handleSubscribeComplete(
+                  connId, svcIdBytes, charIdBytes, status == BluetoothGatt.GATT_SUCCESS);
             } else if (desc.getValue() == BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE) {
               mPlatform.handleUnsubscribeComplete(
                   connId, svcIdBytes, charIdBytes, status == BluetoothGatt.GATT_SUCCESS);
@@ -283,10 +286,18 @@ public boolean onSubscribeCharacteristic(int connId, byte[] svcId, byte[] charId
 
     BluetoothGattDescriptor descriptor =
         subscribeChar.getDescriptor(UUID.fromString(CLIENT_CHARACTERISTIC_CONFIG));
-    descriptor.setValue(BluetoothGattDescriptor.ENABLE_INDICATION_VALUE);
-    if (!bluetoothGatt.writeDescriptor(descriptor)) {
-      Log.e(TAG, "writeDescriptor failed");
-      return false;
+    if ((subscribeChar.getProperties() & BluetoothGattCharacteristic.PROPERTY_INDICATE) != 0) {
+      descriptor.setValue(BluetoothGattDescriptor.ENABLE_INDICATION_VALUE);
+      if (!bluetoothGatt.writeDescriptor(descriptor)) {
+        Log.e(TAG, "writeDescriptor failed");
+        return false;
+      }
+    } else if ((subscribeChar.getProperties() & BluetoothGattCharacteristic.PROPERTY_NOTIFY) != 0) {
+      descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
+      if (!bluetoothGatt.writeDescriptor(descriptor)) {
+        Log.e(TAG, "writeDescriptor failed");
+        return false;
+      }
     }
     return true;
   }