Switch from HIDL Composition type to AIDL

In preparation for adding a new Composition type which is only in AIDL.
This change is almost completely mechanical, and should have no impact
on behavior.

Bug: 193170859
Test: existing tests

Change-Id: I1f923fcc8d8e6dff388493a76e31d435638b5255
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index 596666c..82f463e 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -39,6 +39,8 @@
 
 #include "ComposerHal.h"
 
+using aidl::android::hardware::graphics::composer3::Composition;
+
 namespace android {
 
 using android::Fence;
@@ -147,7 +149,7 @@
 
 Error Display::getChangedCompositionTypes(std::unordered_map<HWC2::Layer*, Composition>* outTypes) {
     std::vector<Hwc2::Layer> layerIds;
-    std::vector<Hwc2::IComposerClient::Composition> types;
+    std::vector<Composition> types;
     auto intError = mComposer.getChangedCompositionTypes(
             mId, &layerIds, &types);
     uint32_t numElements = layerIds.size();