Update doc for ADAPTIVE_CRUISE_CONTROL_TARGET_TIME_GAP.

Part of a large doc update. Add doc for new supported value range
APIs. For be backward compatible with older VHAL clients still
using deprecated fields, we still require the old fields to be
populated.

Test: None
Bug: 383184445
Flag: EXEMPT no code change
Change-Id: I1598cb015bb58270fb247befce5010af5d38e2a5
diff --git a/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleProperty.aidl b/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleProperty.aidl
index f04735a..8eb4fe6 100644
--- a/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleProperty.aidl
+++ b/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleProperty.aidl
@@ -6874,9 +6874,17 @@
      * vehicle's front-most point. The actual time gap from a leading vehicle can be above or below
      * this value.
      *
-     * The possible values to set for the target time gap should be specified in configArray in
-     * ascending order. All values must be positive. If the property is writable, all values must be
-     * writable.
+     * The possible values to set for the target time gap at boot time should be specified in
+     * configArray in ascending order. All values must be positive. If the property is writable, all
+     * values must be writable.
+     *
+     * If {@code HasSupportedValueInfo} is not {@code null},
+     * {@code HasSupportedValueInfo.hasSupportedValuesList} must be {@code true}. The supported
+     * values list represents the possible values to set at the current moment.
+     *
+     * If the possible values to set may change dynamically,
+     * {@code HasSupportedValueInfo.hasSupportedValuesList} must be {@code true} and the supported
+     * values list must be implemented.
      *
      * When this property is not available because CC is disabled (i.e. CRUISE_CONTROL_ENABLED is
      * false), this property must return StatusCode#NOT_AVAILABLE_DISABLED. If CRUISE_CONTROL_STATE
@@ -6892,6 +6900,7 @@
      * @access VehiclePropertyAccess.READ_WRITE
      * @access VehiclePropertyAccess.READ
      * @unit VehicleUnit.MILLI_SECS
+     * @legacy_supported_values_in_config
      * @version 2
      */
     ADAPTIVE_CRUISE_CONTROL_TARGET_TIME_GAP =