Camera: Docs: Improve info on key removal in CameraCharacteristics

Test: m offline-sdk-docs
Bug: 143565873
Change-Id: I559cf028ec3540df7a851ab344072b7637913550

core/java/android/hardware/camera2/CameraCharacteristics.java

@@ -43,6 +43,10 @@ import java.util.Set;
  * through the {@link CameraManager CameraManager}
  * interface with {@link CameraManager#getCameraCharacteristics}.</p>
  *
+ * <p>When obtained by a client that does not hold the CAMERA permission, some metadata values are
+ * not included. The list of keys that require the permission is given by
+ * {@link #getKeysNeedingPermission}.</p>
+ *
  * <p>{@link CameraCharacteristics} objects are immutable.</p>
  *
  * @see CameraDevice

core/java/android/hardware/camera2/CameraManager.java

@@ -362,6 +362,11 @@ public final class CameraManager {
      * cameras that can only be used as part of logical multi-camera. These cameras cannot be
      * opened directly via {@link #openCamera}</p>
      *
+     * <p>Also starting with API level 29, while most basic camera information is still available
+     * even without the CAMERA permission, some values are not available to apps that do not hold
+     * that permission. The keys not available are listed by
+     * {@link CameraCharacteristics#getKeysNeedingPermission}.</p>
+     *
      * @param cameraId The id of the camera device to query. This could be either a standalone
      * camera ID which can be directly opened by {@link #openCamera}, or a physical camera ID that
      * can only used as part of a logical multi-camera.