Add MOBILE_DATA_POLICY_AUTO_DATA_SWITCH

The feature only applies to non-DDS. If enabled, we automatically switch to the non-DDS for data traffic when it has better availability than the DDS.

Test: cts
Bug: 258510998
Change-Id: Id827b3e253b637273504d87c8db64893c7b70924
Merged-In: Id827b3e253b637273504d87c8db64893c7b70924
(cherry picked from commit 837daa5cd1)

telephony/java/android/telephony/TelephonyManager.java

@@ -15379,12 +15379,29 @@ public class TelephonyManager {
     @SystemApi
     public static final int MOBILE_DATA_POLICY_MMS_ALWAYS_ALLOWED = 2;
 
+    /**
+     * Allow switching mobile data to the non-default SIM if the non-default SIM has better
+     * availability.
+     *
+     * This is used for temporarily allowing data on the non-default data SIM when on-default SIM
+     * has better availability on DSDS devices, where better availability means strong
+     * signal/connectivity.
+     * If this policy is enabled, data will be temporarily enabled on the non-default data SIM,
+     * including during any voice calls(equivalent to enabling
+     * {@link #MOBILE_DATA_POLICY_DATA_ON_NON_DEFAULT_DURING_VOICE_CALL}).
+     *
+     * This policy can be enabled and disabled via {@link #setMobileDataPolicyEnabled}.
+     * @hide
+     */
+    public static final int MOBILE_DATA_POLICY_AUTO_DATA_SWITCH = 3;
+
     /**
      * @hide
      */
     @IntDef(prefix = { "MOBILE_DATA_POLICY_" }, value = {
             MOBILE_DATA_POLICY_DATA_ON_NON_DEFAULT_DURING_VOICE_CALL,
             MOBILE_DATA_POLICY_MMS_ALWAYS_ALLOWED,
+            MOBILE_DATA_POLICY_AUTO_DATA_SWITCH,
     })
     @Retention(RetentionPolicy.SOURCE)
     public @interface MobileDataPolicy { }