SurfaceFlinger: add getAllowedDisplayConfigs

Add an API to ISurfaceComposer to get allowed display configurations.

Test: manual test that calls getAllowedDisplayConfigs()
Bug: 122905403
Change-Id: Ieeb04f0d002ecfb2dbb0acd22ef6f659806c3950
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index dae7736..6db3c9c 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -682,6 +682,10 @@
                                       const std::vector<int32_t>& /*allowedConfigs*/) override {
         return NO_ERROR;
     }
+    status_t getAllowedDisplayConfigs(const sp<IBinder>& /*displayToken*/,
+                                      std::vector<int32_t>* /*outAllowedConfigs*/) override {
+        return NO_ERROR;
+    }
 
 protected:
     IBinder* onAsBinder() override { return nullptr; }