Replace synchronous calls to shared prefs with async calls.

Also, make a copy of protected data to prevent accidental changes
from outside callers.

Bug: 130525551
Test: Manual.
Change-Id: I7b6efa32bc6db88b79579effaa7ffe1466a80380

packages/SystemUI/shared/src/com/android/systemui/shared/plugins/PluginPrefs.java

@@ -42,12 +42,12 @@ public class PluginPrefs {
     }
 
     public Set<String> getPluginList() {
-        return mPluginActions;
+        return new ArraySet<>(mPluginActions);
     }
 
     public synchronized void addAction(String action) {
         if (mPluginActions.add(action)){
-            mSharedPrefs.edit().putStringSet(PLUGIN_ACTIONS, mPluginActions).commit();
+            mSharedPrefs.edit().putStringSet(PLUGIN_ACTIONS, mPluginActions).apply();
         }
     }
 
@@ -56,6 +56,6 @@ public class PluginPrefs {
     }
 
     public static void setHasPlugins(Context context) {
-        context.getSharedPreferences(PREFS, 0).edit().putBoolean(HAS_PLUGINS, true).commit();
+        context.getSharedPreferences(PREFS, 0).edit().putBoolean(HAS_PLUGINS, true).apply();
     }
 }