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/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 5a376da..0cd3962 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -844,7 +844,7 @@
         return NO_ERROR;
     }
     status_t setDesiredDisplayConfigSpecs(const sp<IBinder>& /*displayToken*/,
-                                          int32_t /*defaultConfig*/,
+                                          int32_t /*defaultConfig*/, bool /*allowGroupSwitching*/,
                                           float /*primaryRefreshRateMin*/,
                                           float /*primaryRefreshRateMax*/,
                                           float /*appRequestRefreshRateMin*/,
@@ -853,6 +853,7 @@
     }
     status_t getDesiredDisplayConfigSpecs(const sp<IBinder>& /*displayToken*/,
                                           int32_t* /*outDefaultConfig*/,
+                                          bool* /*outAllowGroupSwitching*/,
                                           float* /*outPrimaryRefreshRateMin*/,
                                           float* /*outPrimaryRefreshRateMax*/,
                                           float* /*outAppRequestRefreshRateMin*/,