SF: Remove HWC plumbing for virtual display mirror

Replace the parameter, which is only relevant to SF-ARC, with a simpler
hook (virtual processDisplayAdded) that is closer to HWC-less overrides
for display creation.

Bug: 182939859
Test: Build
Change-Id: I9c8f84ec900d6538d9130c23a75ee79d1aefe13e
diff --git a/services/surfaceflinger/tests/unittests/DisplayTransactionTestHelpers.h b/services/surfaceflinger/tests/unittests/DisplayTransactionTestHelpers.h
index 6ce281d..de058a4 100644
--- a/services/surfaceflinger/tests/unittests/DisplayTransactionTestHelpers.h
+++ b/services/surfaceflinger/tests/unittests/DisplayTransactionTestHelpers.h
@@ -615,8 +615,8 @@
     }
 
     static void setupHwcVirtualDisplayCreationCallExpectations(DisplayTransactionTest* test) {
-        EXPECT_CALL(*test->mComposer, createVirtualDisplay(Base::WIDTH, Base::HEIGHT, _, _, _))
-                .WillOnce(DoAll(SetArgPointee<4>(Self::HWC_DISPLAY_ID), Return(Error::NONE)));
+        EXPECT_CALL(*test->mComposer, createVirtualDisplay(Base::WIDTH, Base::HEIGHT, _, _))
+                .WillOnce(DoAll(SetArgPointee<3>(Self::HWC_DISPLAY_ID), Return(Error::NONE)));
         EXPECT_CALL(*test->mComposer, setClientTargetSlotCount(_)).WillOnce(Return(Error::NONE));
     }
 };