GameManagerService: Set device_config property on behalf of GameSpace

GTS don't allow any app to have the android.permission.WRITE_DEVICE_CONFIG permission
i.e we can't modify device_config property from our game space.

So write the property to our custom Settings.Secure.GAME_OVERLAY.
Then observe the value changes and set the property to the
device_config from here.

Since GameManagerService is a part of system_server,
GTS will be happy.

Change-Id: I0ebbcd6188411a583fa53904e6153482f342a03e
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

Author: Dhina17

services/core/java/com/android/server/app/GameManagerService.java

@@ -48,6 +48,7 @@
 import android.app.StatsManager;
 import android.app.UidObserver;
 import android.content.BroadcastReceiver;
+import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
@@ -60,6 +61,7 @@
 import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.content.res.XmlResourceParser;
+import android.database.ContentObserver;
 import android.hardware.power.Mode;
 import android.net.Uri;
 import android.os.Binder;
@@ -81,6 +83,7 @@
 import android.os.UserManager;
 import android.provider.DeviceConfig;
 import android.provider.DeviceConfig.Properties;
+import android.provider.Settings;
 import android.text.TextUtils;
 import android.util.ArrayMap;
 import android.util.AtomicFile;
@@ -1600,6 +1603,10 @@ public void onReceive(Context context, Intent intent) {
         mGameDefaultFrameRateValue = (float) mSysProps.getInt(
                 PROPERTY_RO_SURFACEFLINGER_GAME_DEFAULT_FRAME_RATE, 60);
         Slog.v(TAG, "Game Default Frame Rate : " + mGameDefaultFrameRateValue);
+        
+        // Start to observe our Settings.Secure.GAME_OVERLAY
+        // after boot completed.
+        new SettingsObserver(mHandler);
     }
 
     private void sendUserMessage(int userId, int what, String eventForLog, int delayMillis) {
@@ -2372,4 +2379,41 @@ private void handleUidMovedOffTop(int uid) {
             }
         }
     }
+
+    class SettingsObserver extends ContentObserver {
+
+        private final ContentResolver mContentResolver;
+
+        SettingsObserver(Handler handler) {
+            super(handler);
+            mContentResolver = mContext.getContentResolver();
+            mContentResolver.registerContentObserver(Settings.Secure.getUriFor(
+                    "game_overlay"), false, this,
+                    UserHandle.USER_ALL);
+            }
+
+        @Override
+        public void onChange(boolean selfChange, Uri uri) {
+            String newValue = Settings.Secure.getString(mContentResolver,
+                    "game_overlay");
+            // We write key and value of the device_config property as a single string
+            // from our GameSpace.
+            // ';;' is the separator betweeen key and value.
+            // Example: com.libremobileos.game;;mode=2,downscaleFactor=0.7:mode=3,downscaleFactor=0.8
+            // So split the key and value from the string
+            // and set the device_config propery.
+            String[] parsedValues = newValue.split(";;");
+            // Value should contain both package name and config.
+            // Otherwise don't do anything.
+            if (parsedValues.length < 2) return;
+            // We don't need to care about any format and all.
+            // It will be handled by the GamePackageConfiguration while
+            // parsing the device_config property.
+            String packageName = parsedValues[0];
+            String configValue = parsedValues[1];
+            DeviceConfig.setProperty(DeviceConfig.NAMESPACE_GAME_OVERLAY,
+                    packageName, configValue, false);
+        }
+    }
+
 }