Add HWC2::setBlockingRegion

Implement from here down: the blocking region is passed to
HidlComposerHal (which ignores it) and AidlComposerHal (which respects
it).

Depends on Ib0fa41e56196feeff201637d5599830d2565da2b.

Bug: 212736475
Test: TODO (b/213361853)
Change-Id: I991c8e1beca22075ec831f96dff218e6af3d9a08
diff --git a/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h b/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
index ff68053..f66de22 100644
--- a/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
+++ b/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
@@ -75,6 +75,7 @@
     MOCK_METHOD3(setLayerGenericMetadata,
                  Error(const std::string&, bool, const std::vector<uint8_t>&));
     MOCK_METHOD1(setWhitePointNits, Error(float));
+    MOCK_METHOD1(setBlockingRegion, Error(const android::Region&));
 };
 
 } // namespace mock