ICameraProvider@2.6 : Update documentation for getConcurrentStreamingCameraIds.

Bug: 148995918

Test: builds

Change-Id: I89df3be9e15881e081b76d6c0312bc54da931dea
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>
diff --git a/camera/provider/2.6/ICameraProvider.hal b/camera/provider/2.6/ICameraProvider.hal
index 2c79c27..9c46ba0 100644
--- a/camera/provider/2.6/ICameraProvider.hal
+++ b/camera/provider/2.6/ICameraProvider.hal
@@ -56,6 +56,11 @@
      * s720p - min (max output resolution for the given format, 1280 X 720)
      * s1440p - min (max output resolution for the given format, 1920 X 1440)
      *
+     * The camera framework must call this method whenever it gets a
+     * cameraDeviceStatusChange callback adding a new camera device or removing
+     * a camera device known to it. This is so that the camera framework can get new combinations
+     * of camera ids that can stream concurrently, that might have potentially appeared.
+     *
      * @return status Status code for the operation
      * @return cameraIds a list of camera id combinations that support
      *         concurrent stream configurations with the minimum guarantees