LSPosedContext: ensure mResources is initialized when calling getTheme() (#2603)

core/src/main/java/org/lsposed/lspd/impl/LSPosedContext.java

@@ -235,11 +235,13 @@ public class LSPosedContext extends XposedContext {
 
     @Override
     public void setTheme(int resid) {
+        getResources();
         mBase.setTheme(resid);
     }
 
     @Override
     public Resources.Theme getTheme() {
+        getResources();
         return mBase.getTheme();
     }