Fix error in DecorView's ViewConfiguration

In ViewConfiguration, we use isUiContext to verify if a context
is an visual context. However, DecorContext uses Application
context as a base context and return false as intended.
This patch overrides isUiContext to report context#isUiContext
instead.

fixes: 153664027
Test: atest DecorContextTest#testIsUiContextFromVisualDecorContext
Change-Id: Ida26b9617c74dc6997fc2c00d97d3420a0978fc7

core/java/com/android/internal/policy/DecorContext.java

@@ -118,4 +118,13 @@ public class DecorContext extends ContextThemeWrapper {
         }
         return null;
     }
+
+    @Override
+    public boolean isUiContext() {
+        Context context = mContext.get();
+        if (context != null) {
+            return context.isUiContext();
+        }
+        return false;
+    }
 }

core/tests/coretests/src/com/android/internal/policy/DecorContextTest.java

@@ -19,6 +19,7 @@ package com.android.internal.policy;
 import static android.view.Display.DEFAULT_DISPLAY;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import android.app.Activity;
 import android.app.EmptyActivity;
@@ -102,4 +103,14 @@ public final class DecorContextTest {
             assertEquals(expectedWm.mContext, actualWm.mContext);
         });
     }
+
+    @Test
+    public void testIsUiContextFromVisualDecorContext() throws Throwable {
+        mActivityRule.runOnUiThread(() -> {
+            Activity activity = mActivityRule.getActivity();
+            final DecorContext decorContext = new DecorContext(mContext.getApplicationContext(),
+                    (PhoneWindow) activity.getWindow());
+            assertTrue(decorContext.isUiContext());
+        });
+    }
 }