Fix READ_DEVICE_CONFIG permission denied problem in TetheringTests

Bug: 156557122
Test: atest TetheringTests

Change-Id: Id9c0397306f3872fc23520d1354f338035a96dc9
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index 91a6e29..48a600d 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -132,7 +132,7 @@
         isDunRequired = checkDunRequired(ctx);
 
         chooseUpstreamAutomatically = getResourceBoolean(
-                res, R.bool.config_tether_upstream_automatic, false /** default value */);
+                res, R.bool.config_tether_upstream_automatic, false /** defaultValue */);
         preferredUpstreamIfaceTypes = getUpstreamIfaceTypes(res, isDunRequired);
 
         legacyDhcpRanges = getLegacyDhcpRanges(res);
@@ -375,30 +375,31 @@
         // Priority 1: Device config
         // Priority 2: Resource config
         // Priority 3: Default value
-        final boolean resourceValue = getResourceBoolean(
+        final boolean defaultValue = getResourceBoolean(
                 res, R.bool.config_tether_enable_bpf_offload, true /** default value */);
 
-        // Due to the limitation of static mock for testing, using #getProperty directly instead
-        // of getDeviceConfigBoolean. getDeviceConfigBoolean is not invoked because it uses
-        // #getBoolean to get the boolean device config. The test can't know that the returned
-        // boolean value comes from device config or default value (because of null property
-        // string). Because the test would like to verify null property boolean string case,
-        // use DeviceConfig.getProperty here. See also the test case testBpfOffload{*} in
-        // TetheringConfigurationTest.java.
-        final String value = DeviceConfig.getProperty(
-                NAMESPACE_CONNECTIVITY, OVERRIDE_TETHER_ENABLE_BPF_OFFLOAD);
-        return (value != null) ? Boolean.parseBoolean(value) : resourceValue;
+        return getDeviceConfigBoolean(OVERRIDE_TETHER_ENABLE_BPF_OFFLOAD, defaultValue);
     }
 
     private boolean getEnableLegacyDhcpServer(final Resources res) {
         return getResourceBoolean(
-                res, R.bool.config_tether_enable_legacy_dhcp_server, false /** default value */)
-                || getDeviceConfigBoolean(TETHER_ENABLE_LEGACY_DHCP_SERVER);
+                res, R.bool.config_tether_enable_legacy_dhcp_server, false /** defaultValue */)
+                || getDeviceConfigBoolean(
+                TETHER_ENABLE_LEGACY_DHCP_SERVER, false /** defaultValue */);
+    }
+
+    private boolean getDeviceConfigBoolean(final String name, final boolean defaultValue) {
+        // Due to the limitation of static mock for testing, using #getDeviceConfigProperty instead
+        // of DeviceConfig#getBoolean. If using #getBoolean here, the test can't know that the
+        // returned boolean value comes from device config or default value (because of null
+        // property string). See the test case testBpfOffload{*} in TetheringConfigurationTest.java.
+        final String value = getDeviceConfigProperty(name);
+        return value != null ? Boolean.parseBoolean(value) : defaultValue;
     }
 
     @VisibleForTesting
-    protected boolean getDeviceConfigBoolean(final String name) {
-        return DeviceConfig.getBoolean(NAMESPACE_CONNECTIVITY, name, false /** defaultValue */);
+    protected String getDeviceConfigProperty(String name) {
+        return DeviceConfig.getProperty(NAMESPACE_CONNECTIVITY, name);
     }
 
     private Resources getResources(Context ctx, int subId) {
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/EntitlementManagerTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/EntitlementManagerTest.java
index cdd0e24..72fa916 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/EntitlementManagerTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/EntitlementManagerTest.java
@@ -147,9 +147,8 @@
         doReturn(false).when(
                 () -> SystemProperties.getBoolean(
                 eq(EntitlementManager.DISABLE_PROVISIONING_SYSPROP_KEY), anyBoolean()));
-        doReturn(false).when(
-                () -> DeviceConfig.getBoolean(eq(NAMESPACE_CONNECTIVITY),
-                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER), anyBoolean()));
+        doReturn(null).when(
+                () -> DeviceConfig.getProperty(eq(NAMESPACE_CONNECTIVITY), anyString()));
 
         when(mResources.getStringArray(R.array.config_tether_dhcp_range))
                 .thenReturn(new String[0]);
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
index fbfa871..1999ad7 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
@@ -30,7 +30,6 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.Matchers.anyBoolean;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.when;
 
@@ -109,9 +108,9 @@
                 .mockStatic(DeviceConfig.class)
                 .strictness(Strictness.WARN)
                 .startMocking();
-        doReturn(false).when(
-                () -> DeviceConfig.getBoolean(eq(NAMESPACE_CONNECTIVITY),
-                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER), anyBoolean()));
+        doReturn(null).when(
+                () -> DeviceConfig.getProperty(eq(NAMESPACE_CONNECTIVITY),
+                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER)));
 
         when(mResources.getStringArray(R.array.config_tether_dhcp_range)).thenReturn(
                 new String[0]);
@@ -328,9 +327,9 @@
     public void testNewDhcpServerDisabled() {
         when(mResources.getBoolean(R.bool.config_tether_enable_legacy_dhcp_server)).thenReturn(
                 true);
-        doReturn(false).when(
-                () -> DeviceConfig.getBoolean(eq(NAMESPACE_CONNECTIVITY),
-                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER), anyBoolean()));
+        doReturn("false").when(
+                () -> DeviceConfig.getProperty(eq(NAMESPACE_CONNECTIVITY),
+                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER)));
 
         final TetheringConfiguration enableByRes =
                 new TetheringConfiguration(mMockContext, mLog, INVALID_SUBSCRIPTION_ID);
@@ -338,9 +337,9 @@
 
         when(mResources.getBoolean(R.bool.config_tether_enable_legacy_dhcp_server)).thenReturn(
                 false);
-        doReturn(true).when(
-                () -> DeviceConfig.getBoolean(eq(NAMESPACE_CONNECTIVITY),
-                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER), anyBoolean()));
+        doReturn("true").when(
+                () -> DeviceConfig.getProperty(eq(NAMESPACE_CONNECTIVITY),
+                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER)));
 
         final TetheringConfiguration enableByDevConfig =
                 new TetheringConfiguration(mMockContext, mLog, INVALID_SUBSCRIPTION_ID);
@@ -351,9 +350,9 @@
     public void testNewDhcpServerEnabled() {
         when(mResources.getBoolean(R.bool.config_tether_enable_legacy_dhcp_server)).thenReturn(
                 false);
-        doReturn(false).when(
-                () -> DeviceConfig.getBoolean(eq(NAMESPACE_CONNECTIVITY),
-                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER), anyBoolean()));
+        doReturn("false").when(
+                () -> DeviceConfig.getProperty(eq(NAMESPACE_CONNECTIVITY),
+                eq(TetheringConfiguration.TETHER_ENABLE_LEGACY_DHCP_SERVER)));
 
         final TetheringConfiguration cfg =
                 new TetheringConfiguration(mMockContext, mLog, INVALID_SUBSCRIPTION_ID);
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
index b665acc..7734a3c6 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
@@ -312,8 +312,8 @@
         }
 
         @Override
-        protected boolean getDeviceConfigBoolean(final String name) {
-            return false;
+        protected String getDeviceConfigProperty(final String name) {
+            return null;
         }
 
         @Override