SF: Populate allowGroupSwitching from DM

Currently we use allowGroupSwitching only for testing. This CL
populates its value from DisplayManager so we can use user
setting to change its value.

Bug: 161776333
Test: atest libsurfaceflinger_unittest
Change-Id: I851eaee7f86083d97204cf3553e728350c942dfe
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 5bb5a0d..4f1f1c1 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -583,11 +583,12 @@
                                        const sp<IRegionSamplingListener>& listener) override;
     status_t removeRegionSamplingListener(const sp<IRegionSamplingListener>& listener) override;
     status_t setDesiredDisplayConfigSpecs(const sp<IBinder>& displayToken, int32_t displayModeId,
-                                          float primaryRefreshRateMin, float primaryRefreshRateMax,
+                                          bool allowGroupSwitching, float primaryRefreshRateMin,
+                                          float primaryRefreshRateMax,
                                           float appRequestRefreshRateMin,
                                           float appRequestRefreshRateMax) override;
     status_t getDesiredDisplayConfigSpecs(const sp<IBinder>& displayToken,
-                                          int32_t* outDefaultConfig,
+                                          int32_t* outDefaultConfig, bool* outAllowGroupSwitching,
                                           float* outPrimaryRefreshRateMin,
                                           float* outPrimaryRefreshRateMax,
                                           float* outAppRequestRefreshRateMin,