Clarify the video API "setZoom" ratio.

This should ideally be a valid in terms of the reported camera
characteristics.

Test: Docs only change
Bug: 190804553
Change-Id: I35e0148e6e9d90d991b556e5c6db4bbd77ce39a0
diff --git a/telecomm/java/android/telecom/InCallService.java b/telecomm/java/android/telecom/InCallService.java
index 0ff288b..5e3d26a 100644
--- a/telecomm/java/android/telecom/InCallService.java
+++ b/telecomm/java/android/telecom/InCallService.java
@@ -764,11 +764,13 @@
         public abstract void setDeviceOrientation(int rotation);
 
         /**
-         * Sets camera zoom ratio.
+         * Sets the camera zoom ratio.
          * <p>
          * Handled by {@link Connection.VideoProvider#onSetZoom(float)}.
          *
-         * @param value The camera zoom ratio.
+         * @param value The camera zoom ratio; for the current camera, should be a value in the
+         * range defined by
+         * {@link android.hardware.camera2.CameraCharacteristics#CONTROL_ZOOM_RATIO_RANGE}.
          */
         public abstract void setZoom(float value);