Fallback should be evaluated for each preference

1) alowFallback flag was incorrectly not reset while setting profile
   preference. Corrected it.

2) Threw exception if default preference and enterprise preference are
set together

3) renamed clearUser to withoutUser

Bug: 231670730
Test: ConnectivityServiceTest

Change-Id: Iaf49237bdc791c7e1dd884d069eff64e74757477
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index fccb2a6..8e9d4d4 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -10677,7 +10677,10 @@
         Objects.requireNonNull(profile);
 
         if (preferences.size() == 0) {
-            preferences.add((new ProfileNetworkPreference.Builder()).build());
+            final ProfileNetworkPreference pref = new ProfileNetworkPreference.Builder()
+                    .setPreference(ConnectivityManager.PROFILE_NETWORK_PREFERENCE_DEFAULT)
+                    .build();
+            preferences.add(pref);
         }
 
         PermissionUtils.enforceNetworkStackPermission(mContext);
@@ -10695,12 +10698,14 @@
 
         final List<ProfileNetworkPreferenceList.Preference> preferenceList =
                 new ArrayList<ProfileNetworkPreferenceList.Preference>();
-        boolean allowFallback = true;
+        boolean hasDefaultPreference = false;
         for (final ProfileNetworkPreference preference : preferences) {
             final NetworkCapabilities nc;
+            boolean allowFallback = true;
             switch (preference.getPreference()) {
                 case ConnectivityManager.PROFILE_NETWORK_PREFERENCE_DEFAULT:
                     nc = null;
+                    hasDefaultPreference = true;
                     if (preference.getPreferenceEnterpriseId() != 0) {
                         throw new IllegalArgumentException(
                                 "Invalid enterprise identifier in setProfileNetworkPreferences");
@@ -10710,6 +10715,14 @@
                     allowFallback = false;
                     // continue to process the enterprise preference.
                 case ConnectivityManager.PROFILE_NETWORK_PREFERENCE_ENTERPRISE:
+                    // This code is needed even though there is a check later on,
+                    // because isRangeAlreadyInPreferenceList assumes that every preference
+                    // has a UID list.
+                    if (hasDefaultPreference) {
+                        throw new IllegalArgumentException(
+                                "Default profile preference should not be set along with other "
+                                        + "preference");
+                    }
                     if (!isEnterpriseIdentifierValid(preference.getPreferenceEnterpriseId())) {
                         throw new IllegalArgumentException(
                                 "Invalid enterprise identifier in setProfileNetworkPreferences");
@@ -10733,6 +10746,10 @@
             }
             preferenceList.add(new ProfileNetworkPreferenceList.Preference(
                     profile, nc, allowFallback));
+            if (hasDefaultPreference && preferenceList.size() > 1) {
+                throw new IllegalArgumentException(
+                        "Default profile preference should not be set along with other preference");
+            }
         }
         mHandler.sendMessage(mHandler.obtainMessage(EVENT_SET_PROFILE_NETWORK_PREFERENCE,
                 new Pair<>(preferenceList, listener)));
@@ -10777,12 +10794,6 @@
         return false;
     }
 
-    private void validateNetworkCapabilitiesOfProfileNetworkPreference(
-            @Nullable final NetworkCapabilities nc) {
-        if (null == nc) return; // Null caps are always allowed. It means to remove the setting.
-        ensureRequestableCapabilities(nc);
-    }
-
     private ArraySet<NetworkRequestInfo> createNrisFromProfileNetworkPreferences(
             @NonNull final ProfileNetworkPreferenceList prefs) {
         final ArraySet<NetworkRequestInfo> result = new ArraySet<>();
@@ -10840,10 +10851,9 @@
          * Clear all the existing preferences for the user before applying new preferences.
          *
          */
-        mProfileNetworkPreferences = mProfileNetworkPreferences.clearUser(
+        mProfileNetworkPreferences = mProfileNetworkPreferences.withoutUser(
                 preferenceList.get(0).user);
         for (final ProfileNetworkPreferenceList.Preference preference : preferenceList) {
-            validateNetworkCapabilitiesOfProfileNetworkPreference(preference.capabilities);
             mProfileNetworkPreferences = mProfileNetworkPreferences.plus(preference);
         }