Delay handover tear down due to policy for call

When a handover is not allowed due to handover policy, delay the tear down until the call ends.

Fix: 270895912
Test: basic voice call + data browsing
Change-Id: I7c3a850fb2ad18843b57f9147cdf1558e3b56668
diff --git a/flags/data.aconfig b/flags/data.aconfig
index 9a5b506..c769bcc 100644
--- a/flags/data.aconfig
+++ b/flags/data.aconfig
@@ -1 +1,8 @@
 package: "com.android.internal.telephony.flags"
+
+flag {
+  name: "relax_ho_teardown"
+  namespace: "telephony"
+  description: "Relax handover tear down if the device is currently in voice call."
+  bug: "270895912"
+}
\ No newline at end of file
diff --git a/src/java/com/android/internal/telephony/data/DataEvaluation.java b/src/java/com/android/internal/telephony/data/DataEvaluation.java
index eaaf0a5..6858c6a 100644
--- a/src/java/com/android/internal/telephony/data/DataEvaluation.java
+++ b/src/java/com/android/internal/telephony/data/DataEvaluation.java
@@ -155,6 +155,21 @@
     }
 
     /**
+     * Check if all the disallowed reasons are a subset of the given reason.
+     *
+     * @param reasons The given reason to check
+     * @return {@code true} if it doesn't contain any disallowed reasons other than the given
+     * reasons.
+     */
+    public boolean isSubsetOf(DataDisallowedReason... reasons) {
+        int matched = 0;
+        for (DataDisallowedReason requestedReason : reasons) {
+            if (mDataDisallowedReasons.contains(requestedReason)) matched++;
+        }
+        return matched == mDataDisallowedReasons.size();
+    }
+
+    /**
      * Check if the any of the disallowed reasons match one of the provided reason.
      *
      * @param reasons The given reasons to check.
diff --git a/src/java/com/android/internal/telephony/data/DataNetworkController.java b/src/java/com/android/internal/telephony/data/DataNetworkController.java
index d13aaf2..3073f49 100644
--- a/src/java/com/android/internal/telephony/data/DataNetworkController.java
+++ b/src/java/com/android/internal/telephony/data/DataNetworkController.java
@@ -3236,9 +3236,12 @@
             logl("Start handover " + dataNetwork + " to "
                     + AccessNetworkConstants.transportTypeToString(targetTransport));
             dataNetwork.startHandover(targetTransport, dataHandoverRetryEntry);
-        } else if (dataEvaluation.containsOnly(DataDisallowedReason.NOT_IN_SERVICE)
-                && dataNetwork.shouldDelayImsTearDownDueToInCall()) {
-            // We try to preserve voice call in the case of temporary preferred transport mismatch
+        } else if (dataNetwork.shouldDelayImsTearDownDueToInCall()
+                && (dataEvaluation.containsOnly(DataDisallowedReason.NOT_IN_SERVICE)
+                || mFeatureFlags.relaxHoTeardown() && dataEvaluation.isSubsetOf(
+                        DataDisallowedReason.NOT_IN_SERVICE,
+                        DataDisallowedReason.NOT_ALLOWED_BY_POLICY))) {
+            // We try our best to preserve the voice call by retrying later
             if (dataHandoverRetryEntry != null) {
                 dataHandoverRetryEntry.setState(DataRetryEntry.RETRY_STATE_FAILED);
             }
diff --git a/tests/telephonytests/src/com/android/internal/telephony/data/DataEvaluationTest.java b/tests/telephonytests/src/com/android/internal/telephony/data/DataEvaluationTest.java
index 63f3e4f..6d4c0c1 100644
--- a/tests/telephonytests/src/com/android/internal/telephony/data/DataEvaluationTest.java
+++ b/tests/telephonytests/src/com/android/internal/telephony/data/DataEvaluationTest.java
@@ -16,10 +16,10 @@
 
 package com.android.internal.telephony.data;
 
-import com.android.internal.telephony.TelephonyTest;
-
 import static com.google.common.truth.Truth.assertThat;
 
+import com.android.internal.telephony.TelephonyTest;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -59,4 +59,32 @@
                 DataEvaluation.DataDisallowedReason.DATA_DISABLED);
         assertThat(mDataEvaluationUT.getDataDisallowedReasons().size()).isEqualTo(1);
     }
+
+
+    @Test
+    public void testIsSubsetOf() {
+        mDataEvaluationUT = new DataEvaluation(DataEvaluation.DataEvaluationReason.DATA_RETRY);
+        assertThat(mDataEvaluationUT.isSubsetOf(
+                DataEvaluation.DataDisallowedReason.ROAMING_DISABLED)).isTrue();
+        mDataEvaluationUT.addDataDisallowedReason(
+                DataEvaluation.DataDisallowedReason.DATA_DISABLED);
+        assertThat(mDataEvaluationUT.isSubsetOf(
+                DataEvaluation.DataDisallowedReason.DATA_DISABLED)).isTrue();
+        assertThat(mDataEvaluationUT.isSubsetOf(
+                DataEvaluation.DataDisallowedReason.ROAMING_DISABLED)).isFalse();
+    }
+
+    @Test
+    public void testContainsOnly() {
+        mDataEvaluationUT = new DataEvaluation(DataEvaluation.DataEvaluationReason.DATA_RETRY);
+        assertThat(mDataEvaluationUT.containsOnly(
+                DataEvaluation.DataDisallowedReason.ROAMING_DISABLED)).isFalse();
+        mDataEvaluationUT.addDataDisallowedReason(
+                DataEvaluation.DataDisallowedReason.DATA_DISABLED);
+        assertThat(mDataEvaluationUT.containsOnly(
+                DataEvaluation.DataDisallowedReason.DATA_DISABLED)).isTrue();
+        assertThat(mDataEvaluationUT.containsOnly(
+                DataEvaluation.DataDisallowedReason.ROAMING_DISABLED)).isFalse();
+    }
+
 }
diff --git a/tests/telephonytests/src/com/android/internal/telephony/data/DataNetworkControllerTest.java b/tests/telephonytests/src/com/android/internal/telephony/data/DataNetworkControllerTest.java
index d25a504..5e7213b 100644
--- a/tests/telephonytests/src/com/android/internal/telephony/data/DataNetworkControllerTest.java
+++ b/tests/telephonytests/src/com/android/internal/telephony/data/DataNetworkControllerTest.java
@@ -2459,8 +2459,7 @@
                 new String[]{"source=EUTRAN, target=IWLAN, type=disallowed, capabilities=MMS|IMS",
                         "source=IWLAN, target=EUTRAN, type=disallowed, capabilities=MMS"});
         // Force data config manager to reload the carrier config.
-        mDataNetworkControllerUT.getDataConfigManager().obtainMessage(
-                1/*EVENT_CARRIER_CONFIG_CHANGED*/).sendToTarget();
+        carrierConfigChanged();
         processAllMessages();
 
         testSetupImsDataNetwork();
@@ -2501,6 +2500,36 @@
     }
 
     @Test
+    public void testHandoverDataNetworkNotAllowedByPolicyDelayDueToVoiceCall() throws Exception {
+        doReturn(true).when(mFeatureFlags).relaxHoTeardown();
+        // Config delay IMS tear down enabled
+        mCarrierConfig.putBoolean(CarrierConfigManager.KEY_DELAY_IMS_TEAR_DOWN_UNTIL_CALL_END_BOOL,
+                true);
+        mCarrierConfig.putStringArray(CarrierConfigManager.KEY_IWLAN_HANDOVER_POLICY_STRING_ARRAY,
+                new String[]{"source=EUTRAN, target=IWLAN, type=disallowed, capabilities=MMS|IMS"});
+        carrierConfigChanged();
+
+        testSetupImsDataNetwork();
+
+        // Ringing an active call, should delay handover tear down
+        doReturn(PhoneConstants.State.RINGING).when(mCT).getState();
+        updateTransport(NetworkCapabilities.NET_CAPABILITY_IMS,
+                AccessNetworkConstants.TRANSPORT_TYPE_WLAN);
+
+        // Verify network is still connected due to active voice call
+        verify(mMockedWwanDataServiceManager, never()).deactivateDataCall(anyInt(),
+                eq(DataService.REQUEST_REASON_NORMAL), any(Message.class));
+
+        // Verify tear down after call ends
+        doReturn(PhoneConstants.State.IDLE).when(mCT).getState();
+        mDataNetworkControllerUT.obtainMessage(EVENT_VOICE_CALL_ENDED).sendToTarget();
+        processAllFutureMessages();
+
+        verify(mMockedWwanDataServiceManager).deactivateDataCall(anyInt(),
+                eq(DataService.REQUEST_REASON_NORMAL), any(Message.class));
+    }
+
+    @Test
     public void testHandoverDataNetworkNotAllowedByRoamingPolicy() throws Exception {
         mCarrierConfig.putStringArray(CarrierConfigManager.KEY_IWLAN_HANDOVER_POLICY_STRING_ARRAY,
                 new String[]{"source=EUTRAN|NGRAN|IWLAN, target=EUTRAN|NGRAN|IWLAN, roaming=true, "